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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.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 (91, 93) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["product_id", "lang_code"],
      "rows": 2,
      "filtered": 100,
      "index_condition": "cscart_product_descriptions.product_id in (91,93) and cscart_product_descriptions.lang_code = 'en'"
    }
  }
}

Result

product_id	short_description	full_description	meta_keywords	meta_description	search_words	promo_text
91	Spearmint Orange will set you to smiling with every sniff. The menthol in spearmint is relaxing and the orange adds a sweetness for a complete aroma. Shea butter makes the bar soften and moisturize skin.		Spearmint Orange soap	"Winning mint and citrus combination!" "With moisturizing shea butter and creamy lather. Buy 6 get 1 free. Free S&H $49 orders. Herbaria offers a full spectrum of good face and body soaps plus other personal products you can trust.
93	To make this highly enjoyable soap, we combine the healing benefits of oatmeal with three fragrant varieties of mint: cornmint, spearmint and peppermint. Cornmint (Mentha arvensis), is a natural source of menthol and makes this bar refreshing and invigorating. The mints may help relieve tension and headaches. Oatmeal provides the soap with well known exfoliating and moisturizing properties. To further pamper your skin, we incorporate cocoa butter, a rich emollient. The result is a creamy bathing experience that delivers superb cleansing and aromatic satisfaction. You will like the look of the soap, too. The handsome bar is amply textured not only with oatmeal but also with flecks of dried mint.		Triple Mint Oatmeal soap	Refreshing essential oils and moisturizing cocoa butter in creamy lather. Long lasting bars. Exfoliating oatmeal. Buy 6 get 1 free. Herbaria offers a full spectrum of excellent face and body soaps plus other personal products.