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 (
    93470, 93471, 93472, 93473, 93474, 93475, 
    93476, 93477, 93478, 93479, 93480, 
    93481, 93482, 93483, 93484, 93485, 
    93486, 93487, 93488, 93489, 93490, 
    93491, 93492, 93493, 93494, 93495, 
    93496, 93497, 93498, 93499, 93500, 
    93501, 93502, 93503, 93504, 93505, 
    93506, 93507, 93508, 93509, 93510, 
    93511, 93512, 93513, 93514, 93533, 
    93534, 93535
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00079

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "25.94"
    },
    "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": "21.14",
        "eval_cost": "4.80",
        "prefix_cost": "25.94",
        "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 (93470,93471,93472,93473,93474,93475,93476,93477,93478,93479,93480,93481,93482,93483,93484,93485,93486,93487,93488,93489,93490,93491,93492,93493,93494,93495,93496,93497,93498,93499,93500,93501,93502,93503,93504,93505,93506,93507,93508,93509,93510,93511,93512,93513,93514,93533,93534,93535)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
93470
93471
93472
93473
93474
93475
93476
93477
93478
93479
93480
93481
93482
93483
93484
93485
93486
93487
93488
93489
93490
93491
93492
93493
93494
93495
93496
93497
93498
93499
93500
93501
93502
93503
93504
93505
93506
93507
93508
93509
93510
93511
93512
93513
93514
93533
93534
93535