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 (
    95409, 95410, 95411, 95412, 95413, 95414, 
    95415, 95416, 95417, 95418, 95419, 
    95420, 95421, 95422, 95423, 95448, 
    96123, 96130, 96202, 96203, 96204, 
    96205, 96210, 96211, 96510, 96511, 
    96512, 96513, 96514, 96515
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00081

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 (95409,95410,95411,95412,95413,95414,95415,95416,95417,95418,95419,95420,95421,95422,95423,95448,96123,96130,96202,96203,96204,96205,96210,96211,96510,96511,96512,96513,96514,96515)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}