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 (
    98164, 98165, 98166, 98167, 98168, 98224, 
    98225, 98226, 98227, 98228, 98234, 
    98235, 98236, 98237, 98238, 98239, 
    98240, 98241, 98242, 98243, 98244, 
    98245, 98246, 98247
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00059

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "12.97"
    },
    "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": "10.57",
        "eval_cost": "2.40",
        "prefix_cost": "12.97",
        "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 (98164,98165,98166,98167,98168,98224,98225,98226,98227,98228,98234,98235,98236,98237,98238,98239,98240,98241,98242,98243,98244,98245,98246,98247)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
98164
98165
98166
98167
98168
98224
98225
98226
98227
98228
98234
98235
98236
98237
98238
98239
98240
98241
98242
98243
98244
98245
98246
98247