SELECT 
  cscart_product_descriptions.product_id, 
  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 (326, 525, 352, 307, 255) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "product_id"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["product_id", "lang_code"],
      "rows": 5,
      "filtered": 100,
      "index_condition": "cscart_product_descriptions.product_id in (326,525,352,307,255) and cscart_product_descriptions.lang_code = 'en'"
    }
  }
}

Result

product_id meta_keywords meta_description search_words promo_text
255 Camera,head, ballhead, tripod, gitzo, Arca Swiss, RRS, KIRK, Wimberley, foba Fine Art Quality, Professional Ball Head Markins Q3i-BK Knob Shoe
307 Camera, Tripod, Head, Quick, Shoe, Clamp, Plate, Arca-Swiss, rrs, kirk, foba, universal Markins PU-40 is a universal style camera plate for medium sized SLR cameras. It has a rubber bumpons for anti-twisting.
326 Camera, Lens, Tripod, Head, Quick, Shoe, Clamp, Plate, Foot, Arca-Swiss, rrs, kirk, foba Markins PL-75 is a 3.0in (75mm) long anti-twist flange style lens plate.
352
525 Camera,head, ballhead, tripod, gitzo, Arca Swiss, RRS, KIRK, Wimberley, foba Fine Art Quality, Professional Ball Head Markins Q3iQ-BL Lever Shoe