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 (
    87078, 87123, 87124, 87125, 87126, 87127, 
    87128, 87129, 86906, 86907, 86908, 
    86909, 86910, 86911, 86967, 86968, 
    86969, 86970, 86971, 86972, 87028, 
    87029, 87030, 87031, 87032, 87033, 
    87087, 87088, 87089, 87090, 87091, 
    87092, 86920, 86921, 86922, 86923, 
    86924, 86925, 86926, 86981, 86982, 
    86983, 86984, 86985, 86986, 86987, 
    87042, 87043
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00048

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 (87078,87123,87124,87125,87126,87127,87128,87129,86906,86907,86908,86909,86910,86911,86967,86968,86969,86970,86971,86972,87028,87029,87030,87031,87032,87033,87087,87088,87089,87090,87091,87092,86920,86921,86922,86923,86924,86925,86926,86981,86982,86983,86984,86985,86986,86987,87042,87043)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}