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 (
    94805, 94806, 94809, 94832, 95753, 95786, 
    95788, 95885, 95886, 95887, 95888, 
    96117, 96118, 96176, 98036, 98037, 
    98038, 98229, 98233, 98325, 98882, 
    98883, 98884, 98885
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "10.82"
    },
    "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": 24,
      "rows_produced_per_join": 24,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "8.42",
        "eval_cost": "2.40",
        "prefix_cost": "10.82",
        "data_read_per_join": "91K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (94805,94806,94809,94832,95753,95786,95788,95885,95886,95887,95888,96117,96118,96176,98036,98037,98038,98229,98233,98325,98882,98883,98884,98885)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
94805
94806
94809
94832
95753
95786
95788
95885
95886
95887
95888
96117
96118
96176
98036
98037
98038
98229
98233
98325
98882
98883
98884
98885