SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92f94b5f6c86f18abcb4abecd6e803933eb07625573f8d118d55a46018cfe754' 
  AND token = 'bEYl1VHaQhbX6rAQHJO4ctQzog8LxiOSVi+zckIbxg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}