SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.short_description, 
  IF(
    cscart_product_descriptions.short_description = '' 
    OR cscart_product_descriptions.short_description IS NULL, 
    cscart_product_descriptions.full_description, 
    ''
  ) AS full_description 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    87072, 87073, 87074, 87075, 87076, 87077, 
    87078, 87123, 87124, 87125, 87126, 
    87127, 87128, 87129, 91115, 91117, 
    91121, 91123, 91126, 91128, 91130, 
    91201, 91203, 91207, 91209, 91212, 
    91214, 91216, 91256, 91258
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00074

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "13.52"
    },
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "product_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id",
        "lang_code"
      ],
      "key_length": "9",
      "rows_examined_per_scan": 30,
      "rows_produced_per_join": 30,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "10.52",
        "eval_cost": "3.00",
        "prefix_cost": "13.52",
        "data_read_per_join": "114K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (87072,87073,87074,87075,87076,87077,87078,87123,87124,87125,87126,87127,87128,87129,91115,91117,91121,91123,91126,91128,91130,91201,91203,91207,91209,91212,91214,91216,91256,91258)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}