SELECT 
  cscart_bm_snapping.grid_id as grid_id, 
  cscart_bm_snapping.block_id as block_id, 
  IFNULL(
    dynamic_object_content.content, 
    default_content.content
  ) as content, 
  IFNULL(
    dynamic_object_content.object_id, 
    default_content.object_id
  ) AS object_id, 
  IFNULL(
    dynamic_object_content.object_type, 
    default_content.object_type
  ) AS object_type, 
  cscart_bm_block_statuses.object_ids as object_ids, 
  cscart_bm_snapping.*, 
  cscart_bm_blocks.*, 
  cscart_bm_blocks_descriptions.* 
FROM 
  cscart_bm_snapping 
  LEFT JOIN cscart_bm_blocks ON cscart_bm_blocks.block_id = cscart_bm_snapping.block_id 
  LEFT JOIN cscart_bm_block_statuses ON cscart_bm_snapping.snapping_id = cscart_bm_block_statuses.snapping_id 
  AND cscart_bm_block_statuses.object_type LIKE 'cp_blog_categories' 
  LEFT JOIN cscart_bm_blocks_descriptions ON cscart_bm_blocks.block_id = cscart_bm_blocks_descriptions.block_id 
  LEFT JOIN cscart_bm_blocks_content AS default_content ON cscart_bm_blocks.block_id = default_content.block_id 
  AND cscart_bm_blocks_descriptions.lang_code = default_content.lang_code 
  AND default_content.snapping_id = 0 
  AND default_content.object_id = 0 
  AND default_content.object_type like '' 
  LEFT JOIN cscart_bm_blocks_content AS dynamic_object_content ON cscart_bm_blocks.block_id = dynamic_object_content.block_id 
  AND cscart_bm_blocks_descriptions.lang_code = dynamic_object_content.lang_code 
  AND dynamic_object_content.object_id = 2 
  AND dynamic_object_content.object_type like 'cp_blog_categories' 
WHERE 
  cscart_bm_snapping.grid_id IN (
    521, 522, 523, 527, 524, 525, 526, 528, 
    531, 536, 532, 533, 534, 535, 537, 538, 
    764, 765, 766
  ) 
  AND cscart_bm_blocks_descriptions.lang_code = 'ru' 
  AND cscart_bm_blocks.company_id = 1 
ORDER BY 
  cscart_bm_snapping.order, 
  cscart_bm_snapping.block_id

Query time 0.00099

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "292.01"
    },
    "ordering_operation": {
      "using_filesort": true,
      "cost_info": {
        "sort_cost": "12.00"
      },
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_bm_snapping",
            "access_type": "range",
            "possible_keys": [
              "grid_id"
            ],
            "key": "grid_id",
            "used_key_parts": [
              "grid_id"
            ],
            "key_length": "4",
            "rows_examined_per_scan": 60,
            "rows_produced_per_join": 60,
            "filtered": "100.00",
            "index_condition": "(`44mm_ru`.`cscart_bm_snapping`.`grid_id` in (521,522,523,527,524,525,526,528,531,536,532,533,534,535,537,538,764,765,766))",
            "cost_info": {
              "read_cost": "91.01",
              "eval_cost": "12.00",
              "prefix_cost": "103.01",
              "data_read_per_join": "46K"
            },
            "used_columns": [
              "snapping_id",
              "block_id",
              "grid_id",
              "wrapper",
              "user_class",
              "order",
              "status"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_bm_block_statuses",
            "access_type": "ref",
            "possible_keys": [
              "snapping_id"
            ],
            "key": "snapping_id",
            "used_key_parts": [
              "snapping_id"
            ],
            "key_length": "4",
            "ref": [
              "44mm_ru.cscart_bm_snapping.snapping_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 60,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "60.00",
              "eval_cost": "12.00",
              "prefix_cost": "175.01",
              "data_read_per_join": "7K"
            },
            "used_columns": [
              "snapping_id",
              "object_ids",
              "object_type"
            ],
            "attached_condition": "<if>(is_not_null_compl(cscart_bm_block_statuses), ((`44mm_ru`.`cscart_bm_snapping`.`snapping_id` = `44mm_ru`.`cscart_bm_block_statuses`.`snapping_id`) and (`44mm_ru`.`cscart_bm_block_statuses`.`object_type` like 'cp_blog_categories')), true)"
          }
        },
        {
          "table": {
            "table_name": "cscart_bm_blocks",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "block_id"
            ],
            "key_length": "4",
            "ref": [
              "44mm_ru.cscart_bm_snapping.block_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 6,
            "filtered": "10.00",
            "cost_info": {
              "read_cost": "60.00",
              "eval_cost": "1.20",
              "prefix_cost": "247.01",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "block_id",
              "type",
              "properties",
              "company_id",
              "storefront_id",
              "ab__ab_hide_block"
            ],
            "attached_condition": "(`44mm_ru`.`cscart_bm_blocks`.`company_id` = 1)"
          }
        },
        {
          "table": {
            "table_name": "cscart_bm_blocks_descriptions",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "block_id",
              "lang_code"
            ],
            "key_length": "10",
            "ref": [
              "44mm_ru.cscart_bm_snapping.block_id",
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 6,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "6.00",
              "eval_cost": "1.20",
              "prefix_cost": "254.21",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "block_id",
              "lang_code",
              "name"
            ]
          }
        },
        {
          "table": {
            "table_name": "default_content",
            "access_type": "ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "block_id",
              "snapping_id",
              "lang_code",
              "object_id"
            ],
            "key_length": "18",
            "ref": [
              "44mm_ru.cscart_bm_snapping.block_id",
              "const",
              "44mm_ru.cscart_bm_blocks_descriptions.lang_code",
              "const"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 6,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "8.04",
              "eval_cost": "1.20",
              "prefix_cost": "263.45",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "snapping_id",
              "object_id",
              "object_type",
              "block_id",
              "lang_code",
              "content"
            ],
            "attached_condition": "<if>(is_not_null_compl(default_content), (`44mm_ru`.`default_content`.`object_type` like ''), true)"
          }
        },
        {
          "table": {
            "table_name": "dynamic_object_content",
            "access_type": "ref",
            "possible_keys": [
              "PRIMARY"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "block_id"
            ],
            "key_length": "4",
            "ref": [
              "44mm_ru.cscart_bm_snapping.block_id"
            ],
            "rows_examined_per_scan": 2,
            "rows_produced_per_join": 12,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "14.16",
              "eval_cost": "2.40",
              "prefix_cost": "280.01",
              "data_read_per_join": "2K"
            },
            "used_columns": [
              "object_id",
              "object_type",
              "block_id",
              "lang_code",
              "content"
            ],
            "attached_condition": "<if>(is_not_null_compl(dynamic_object_content), ((`44mm_ru`.`dynamic_object_content`.`object_id` = 2) and (`44mm_ru`.`dynamic_object_content`.`lang_code` = `44mm_ru`.`cscart_bm_blocks_descriptions`.`lang_code`) and (`44mm_ru`.`dynamic_object_content`.`object_type` like 'cp_blog_categories')), true)"
          }
        }
      ]
    }
  }
}