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 (
    98086, 98087, 98088, 98089, 98090, 98091, 
    98092, 98093, 98094, 98095, 98096, 
    98097, 98098, 98099, 98100, 98101, 
    98102, 98103, 98104, 98105, 98106, 
    98115, 98116, 98117, 98118, 98119, 
    98120, 98121, 98130, 98131, 98132, 
    98133, 98134, 98135, 98136, 98137, 
    98170, 98173, 98175, 98343, 98344, 
    98345, 98346, 98347, 98348, 98349, 
    98350, 98383
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00089

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 (98086,98087,98088,98089,98090,98091,98092,98093,98094,98095,98096,98097,98098,98099,98100,98101,98102,98103,98104,98105,98106,98115,98116,98117,98118,98119,98120,98121,98130,98131,98132,98133,98134,98135,98136,98137,98170,98173,98175,98343,98344,98345,98346,98347,98348,98349,98350,98383)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
98086
98087
98088
98089
98090
98091
98092
98093
98094
98095
98096
98097
98098
98099
98100
98101
98102
98103
98104
98105
98106
98115
98116
98117
98118
98119
98120
98121
98130
98131
98132
98133
98134
98135
98136
98137
98170
98173
98175
98343
98344
98345
98346
98347
98348
98349
98350
98383