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 (
    94656, 94657, 94658, 94666, 94667, 94668, 
    94669, 94670, 95314, 95378, 95379, 
    95380, 95381, 95382, 95383, 95384, 
    95385, 95386, 95387, 95388, 95389, 
    95390, 95391, 95402, 95403, 95404, 
    95405, 95406, 95407, 95408, 95409, 
    95410, 95411, 95412, 95413, 95414, 
    95415, 95416, 95417, 95418, 95419, 
    95420, 95421, 95422, 95423, 95448, 
    96123, 96130
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00091

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 (94656,94657,94658,94666,94667,94668,94669,94670,95314,95378,95379,95380,95381,95382,95383,95384,95385,95386,95387,95388,95389,95390,95391,95402,95403,95404,95405,95406,95407,95408,95409,95410,95411,95412,95413,95414,95415,95416,95417,95418,95419,95420,95421,95422,95423,95448,96123,96130)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
94656
94657
94658
94666
94667
94668
94669
94670
95314
95378
95379
95380
95381
95382
95383
95384
95385
95386
95387
95388
95389
95390
95391
95402
95403
95404
95405
95406
95407
95408
95409
95410
95411
95412
95413
95414
95415
95416
95417
95418
95419
95420
95421
95422
95423
95448
96123
96130