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 (
    94606, 94607, 94608, 94609, 94610, 94611, 
    94612, 94613, 94614, 94615, 94616, 
    94617, 94618, 94654, 94655, 94656, 
    94657, 94658, 94666, 94667, 94668, 
    94669, 94670, 94751, 94752, 94753, 
    94754, 94755, 94756, 94757, 94758, 
    94762, 94764, 95314, 95378, 95379, 
    95380, 95381, 95382, 95383, 95384, 
    95385, 95386, 95387, 95388, 95389, 
    95390, 95391
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00088

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 (94606,94607,94608,94609,94610,94611,94612,94613,94614,94615,94616,94617,94618,94654,94655,94656,94657,94658,94666,94667,94668,94669,94670,94751,94752,94753,94754,94755,94756,94757,94758,94762,94764,95314,95378,95379,95380,95381,95382,95383,95384,95385,95386,95387,95388,95389,95390,95391)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
94606
94607
94608
94609
94610
94611
94612
94613
94614
94615
94616
94617
94618
94654
94655
94656
94657
94658
94666
94667
94668
94669
94670
94751
94752
94753
94754
94755
94756
94757
94758
94762
94764
95314
95378
95379
95380
95381
95382
95383
95384
95385
95386
95387
95388
95389
95390
95391