SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.short_description, 
  IF(
    cscart_product_descriptions.short_description = '', 
    cscart_product_descriptions.full_description, 
    ''
  ) AS full_description, 
  cscart_product_descriptions.meta_keywords, 
  cscart_product_descriptions.meta_description, 
  cscart_product_descriptions.search_words, 
  cscart_product_descriptions.promo_text 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (4292, 4293, 4298, 4268, 4301) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "product_id"],
      "key": "product_id",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 5,
      "filtered": 100,
      "index_condition": "cscart_product_descriptions.product_id in (4292,4293,4298,4268,4301)",
      "attached_condition": "cscart_product_descriptions.lang_code = 'en'"
    }
  }
}

Result

product_id short_description full_description meta_keywords meta_description search_words promo_text
4268 <p>3.7V / BT90 / Motorola OEM high capacity lithium ion 1800 mAh battery</p> SL7550 Battery, SL7590 Battery, SL7580; Batteries
4292 <p>Protect standard batteries with this durable replacement cover. </p> SL7550 Battery, SL7590 Battery, SL7580; Batteries
4293 <p>Protect high capacity batteries with this durable replacement cover. </p> SL7550 Battery, SL7590 Battery, SL7580; Batteries, SL7550 battery door cover, SL7590 battery door cover, SL7580 battery door cover, SL7550e battery cover, SL7580e battery cover, SL7590e battery cover, SL7000 battery cover
4298 <p>Motorola PMLN6745A - Battery Cover for BT100 Battery</p> SL7550 Battery, SL7590 Battery, SL7580; Batteries
4301 <p>Standard lithium ion 1370 mAh battery for two-way radios. </p> PMNN4425A, SL7550 Battery, SL7590 Battery, SL7580; Batteries