SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e403a9d59c532f27af8b587f507f9e3d7b8f1adc25127b068d4016dc1d103eca' 
  AND token = 'YlzT6xC+WBbvZ6hZ55bOmfDkxwjPl3zIuqClFeU9T2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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