SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b4dea0509b328ae5eba1ecc429ddeded0da95750c2bd02281e4ef7439bb19282' 
  AND token = 'QlMVlINIUf8YG1O+ZFZCBmOkzGhCm+7F1KqOtT7aF68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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