SELECT 
  cscart_products.* 
FROM 
  cscart_products 
WHERE 
  cscart_products.product_id IN (
    6509, 6508, 32956, 19632, 61415, 68414, 
    30699, 68403, 68436, 69379, 30700, 
    30704
  )

Query time 0.00114

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": 12,
      "filtered": 100,
      "index_condition": "cscart_products.product_id in (6509,6508,32956,19632,61415,68414,30699,68403,68436,69379,30700,30704)"
    }
  }
}