SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa8fc7c0b43f7b03f35916c00dd181a8284c79d4fdb63d60684c464b41e2ac94' 
  AND token = 'PHdC0OBYVZoiaghwNNosY1SmWQwQuW+jMtJHcP+/Iic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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