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 (
    389081, 389083, 389084, 389087, 389088, 
    389089, 389090, 389092, 389094, 389095, 
    389096, 389097, 389100, 389101, 389102, 
    389103, 389104, 389105, 389106, 389109
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00114

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "28.04"
    },
    "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": 20,
      "rows_produced_per_join": 20,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "24.04",
        "eval_cost": "4.00",
        "prefix_cost": "28.04",
        "data_read_per_join": "136K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`webmarco`.`cscart_product_descriptions`.`product_id` in (389081,389083,389084,389087,389088,389089,389090,389092,389094,389095,389096,389097,389100,389101,389102,389103,389104,389105,389106,389109)) and (`webmarco`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
389081 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.
389083 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.
389084 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.
389087 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.
389088 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.
389089 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.
389090 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.
389092 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.
389094 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.
389095 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.
389096 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.
389097 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.
389100 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.
389101 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.
389102 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.
389103 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.
389104 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.
389105 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.
389106 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.
389109 Conquer winter roads with GISLAVED tires, offering a range of options for your car, SUV, or light truck.