SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    10395, 10394, 10393, 10392, 10390, 10389, 
    10388, 10387, 10386, 10384, 10383, 
    10382, 12679, 12678, 12677, 12676, 
    12675, 12674, 12673, 15779
  )

Query time 0.00078

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_products",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 20,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (10395,10394,10393,10392,10390,10389,10388,10387,10386,10384,10383,10382,12679,12678,12677,12676,12675,12674,12673,15779)"
    }
  }
}