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 (
    84708, 84749, 84731, 84732, 84733, 87921, 
    87923, 87933, 87935, 88042, 84720, 
    84723, 84727, 87974, 84271, 84939, 
    84734, 84735, 84938, 84719, 84722, 
    84724, 84744, 84718, 84721, 84937, 
    84936, 87991, 87966, 87922, 87928, 
    87934, 88017, 84856, 84857, 84949, 
    84950, 84690, 84748, 88039, 87905, 
    84691, 87894, 84847, 84854, 84855, 
    87906, 84689, 84945, 84946, 91064, 
    84270, 88033, 88007, 84754, 84755, 
    84943, 84944, 87904, 87910, 87911, 
    87912, 87896, 88034, 84269, 84958, 
    87892, 87897, 84952, 84953, 87909, 
    87916, 87891, 87895, 87903, 87908, 
    87914, 84746, 87893, 87963, 84959, 
    87913, 87917, 88036, 87971, 84756, 
    84757, 88016, 84861, 84862, 87900, 
    87901, 87915, 88088, 88056, 88057
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00200

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "43.24"
    },
    "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": 96,
      "rows_produced_per_join": 96,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "33.64",
        "eval_cost": "9.60",
        "prefix_cost": "43.24",
        "data_read_per_join": "366K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (84708,84749,84731,84732,84733,87921,87923,87933,87935,88042,84720,84723,84727,87974,84271,84939,84734,84735,84938,84719,84722,84724,84744,84718,84721,84937,84936,87991,87966,87922,87928,87934,88017,84856,84857,84949,84950,84690,84748,88039,87905,84691,87894,84847,84854,84855,87906,84689,84945,84946,91064,84270,88033,88007,84754,84755,84943,84944,87904,87910,87911,87912,87896,88034,84269,84958,87892,87897,84952,84953,87909,87916,87891,87895,87903,87908,87914,84746,87893,87963,84959,87913,87917,88036,87971,84756,84757,88016,84861,84862,87900,87901,87915,88088,88056,88057)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}