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, 
  cscart_product_descriptions.unit_name 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (2354, 2356) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00055

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "1.42"
    },
    "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": 2,
      "rows_produced_per_join": 2,
      "filtered": "100.00",
      "index_condition": "((`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_descriptions`.`product_id` in (2354,2356)) and (`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "1.23",
        "eval_cost": "0.20",
        "prefix_cost": "1.43",
        "data_read_per_join": "9K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description",
        "unit_name"
      ]
    }
  }
}

Result

product_id short_description full_description unit_name
2354 <p>The Xiaomi Mi Smart Plug (Zigbee) (Model: ZNCZ04LM) is a Zigbee-enabled smart outlet that transforms regular appliances into smart devices. Paired with a compatible smart hub, it allows for remote control, scheduling, power monitoring, and voice commands via Alexa or Google Assistant. Built from flame-resistant materials and featuring overload protection, it's safe, compact, and ideal for automating lights, heaters, fans, and more within your smart home ecosystem. </p> <p></p>
2356 <p>The Mi Power Strip (3 outlet, 3 USB) is a compact, high-quality surge-protected extension that combines three AC outlets with three smart USB ports in a flame-retardant PC housing. It features smart chips to auto-adjust charging current, independent safety shutters on each outlet, a hidden LED indicator, and overload protection that trips at 10 A/2,500 W. With a durable 1.8 m cable and anti-slip base, it’s ideal for powering multiple devices safely and conveniently. </p> <p></p>