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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 (4725, 4742, 4744, 4743) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00019

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": 4,
      "filtered": 100,
      "index_condition": "cscart_product_descriptions.product_id in (4725,4742,4744,4743)",
      "attached_condition": "cscart_product_descriptions.lang_code = 'en'"
    }
  }
}

Result

product_id	full_description	search_words
4725	<p>This carrying accessory is a spring-action, 2-inch belt clip for the XPR3000, XPR6000, APX1000, APX4000 Series radios. </p>	APX 1000 Case, APX 4000 Case, APX 4000XE Case, XPR 3300 Case, XPR 3500 Case, XPR 6100 Case, XPR 6380 Case, XPR 6550 Case, XPR 6580 Cases, XPR3300e, XPR3500e, XPR6350, XPR6550, XPR6000, XPR6380, XPR6580, XPR7000, XPR7350, XPR7550, XPR7380, XPR7580
4742		XPR 6100 Case, XPR 6380 Case, XPR 6550 Case, XPR 6580 Cases
4743		XPR 6100 Case, XPR 6380 Case, XPR 6550 Case, XPR 6580 Cases
4744		XPR 6100 Case, XPR 6380 Case, XPR 6550 Case, XPR 6580 Cases