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 (
    15098, 13182, 16680, 16559, 14050, 14053, 
    14056, 14058, 14060, 14061, 16728, 
    16560, 888, 16556, 16558, 16557, 14664, 
    16611, 16613, 16612, 16614, 16553, 
    16439, 17204, 14477, 17138, 16615, 
    16622, 16616, 16554, 14478, 13031, 
    15462
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00144

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "23.11"
    },
    "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": 33,
      "rows_produced_per_join": 33,
      "filtered": "100.00",
      "index_condition": "((`dev_yourmart_co_bw`.`cscart_product_descriptions`.`product_id` in (15098,13182,16680,16559,14050,14053,14056,14058,14060,14061,16728,16560,888,16556,16558,16557,14664,16611,16613,16612,16614,16553,16439,17204,14477,17138,16615,16622,16616,16554,14478,13031,15462)) and (`dev_yourmart_co_bw`.`cscart_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "19.81",
        "eval_cost": "3.30",
        "prefix_cost": "23.11",
        "data_read_per_join": "125K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ]
    }
  }
}