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 (
    95889, 95891, 95892, 96120, 96121, 96571, 
    97619, 97621, 97622, 97624, 97626, 
    97627, 97632, 97638, 97704, 98587, 
    98588, 98589, 98878, 98879, 98880, 
    98881, 98886, 98887, 98888, 99110, 
    99120, 99121, 99123, 99125, 99127, 
    99128, 99162, 99171, 99177, 99182, 
    99183, 99203, 99206, 99218, 99221, 
    99222, 99227, 99242, 99243, 99251, 
    99252, 99255
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00095

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "21.63"
    },
    "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": 48,
      "rows_produced_per_join": 48,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "16.83",
        "eval_cost": "4.80",
        "prefix_cost": "21.63",
        "data_read_per_join": "183K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (95889,95891,95892,96120,96121,96571,97619,97621,97622,97624,97626,97627,97632,97638,97704,98587,98588,98589,98878,98879,98880,98881,98886,98887,98888,99110,99120,99121,99123,99125,99127,99128,99162,99171,99177,99182,99183,99203,99206,99218,99221,99222,99227,99242,99243,99251,99252,99255)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}