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 (
    98181, 98182, 98183, 98184, 98185, 98186, 
    98187, 98188, 98189, 98190, 98191, 
    98200, 98201, 98202, 98203, 98204, 
    98205, 98206, 98207, 98327, 98328, 
    98329, 98330, 98331, 98332, 98333, 
    98334, 98335, 98336, 98337, 98338, 
    98339, 98340, 98341, 98342, 98343, 
    98344, 98345, 98346, 98347, 98348, 
    98349, 98350, 98351, 98352, 98353, 
    98354, 98355
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00099

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 (98181,98182,98183,98184,98185,98186,98187,98188,98189,98190,98191,98200,98201,98202,98203,98204,98205,98206,98207,98327,98328,98329,98330,98331,98332,98333,98334,98335,98336,98337,98338,98339,98340,98341,98342,98343,98344,98345,98346,98347,98348,98349,98350,98351,98352,98353,98354,98355)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
98181
98182
98183
98184
98185
98186
98187
98188
98189
98190
98191
98200
98201
98202
98203
98204
98205
98206
98207
98327
98328
98329
98330
98331
98332
98333
98334
98335
98336
98337
98338
98339
98340
98341
98342
98343
98344
98345
98346
98347
98348
98349
98350
98351
98352
98353
98354
98355