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 (2807, 2806, 2802, 2801, 2799) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "2.26"
    },
    "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": 5,
      "rows_produced_per_join": 5,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "1.76",
        "eval_cost": "0.50",
        "prefix_cost": "2.26",
        "data_read_per_join": "19K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`shoptheindependents_com`.`cscart_product_descriptions`.`product_id` in (2807,2806,2802,2801,2799)) and (`shoptheindependents_com`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
2799 <p>This contemporary design book showcases the finest of architectural styles from interior designer Sophie Ashby, whose work is brimming with whimsy, glamour, and eclectic charm.</p>
2801
2802 <p>The Amelia Frame brings a burst of personality to your space with its striking red hue and playful bead detailing along the border. Crafted from quality wood, this frame is perfect for showcasing cherished memories, adding a pop of color to any room with its modern-meets-eclectic design. Whether placed on a shelf or tabletop, the Amelia Frame is a statement piece that elevates your decor.</p>
2806 <p>An off-grid escape for nomads and bohemians alike, Tulum is a Mayan hideaway located on Mexico's Yucatan Peninsula. With 200 photos of its striking sandy beaches, tropical backdrop, and spiritual lifestyle, this coffee table book makes a beautiful gift for the travel enthusiast or world-wanderer.</p>
2807 <p>Take a bow, holiday hosts&nbsp;– the Benedita Collection's bow-adorned pieces make every moment and meal feel like a gift to be unwrapped.</p>