SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '46a8fdf2a2d75dfb230c61e43da5897400812aaf345aedb2ecf501753e6b36b9' 
  AND token = 'weZB883PMnFWUXeVeQrsn9+qtvIj7KXkzbEKFkgleX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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