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 (
    95953, 95954, 95955, 95956, 95957, 95958, 
    95959, 95960, 95961, 95962, 95963, 
    95964, 95965, 95966, 95967, 95968, 
    95969, 95970, 95971, 95972, 95973, 
    95974, 95975, 95976, 95977, 95978, 
    95979, 95980, 95981, 95982
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00089

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "13.52"
    },
    "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": 30,
      "rows_produced_per_join": 30,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "10.52",
        "eval_cost": "3.00",
        "prefix_cost": "13.52",
        "data_read_per_join": "114K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (95953,95954,95955,95956,95957,95958,95959,95960,95961,95962,95963,95964,95965,95966,95967,95968,95969,95970,95971,95972,95973,95974,95975,95976,95977,95978,95979,95980,95981,95982)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
95953
95954
95955
95956
95957
95958
95959
95960
95961
95962
95963
95964
95965
95966
95967
95968
95969
95970
95971
95972
95973
95974
95975
95976
95977
95978
95979
95980
95981
95982