我如何检查我的域名是否已经过户？

我的问题是，我怎么知道我的域是否已经存在并且可以继续调用静态映射API而不使用API​​_KEY参数？

您可以通过尝试加载地图来测试您的域是否已被列入白名单一个API密钥。如果您设法获取静态地图图像，则表示您已被列入白名单。

白名单每天有25000个查询限制，相当于您使用密钥时的免费配额限制。

为了能够监控您的使用情况，并在需要时获得更多配额，最好让您开始使用API​​密钥。然后，您可以查看配额并监控您在Google Developer Console中的使用情况

I have thoroughly read through the updated google API Terms and Conditions:

developers.google/maps/pricing-and-plans/standard-plan-2016-update

Specifically, this excerpt:

Active domains created before June 22, 2016, continue to be able to access the Google Maps JavaScript API, Static Maps API, and Street View Image API without an API key. They are not affected by keyless access being unavailable for new domains.

My question is, how do I figure out if my domain is grandfathered and can continue to call the static maps API without the API_KEY parameter?

You can test if your domain was whitelisted by trying to load a map without an API key. If you manage to get the static map image it means you were whitelisted.

The whitelist has 25000 queries per day limit which is equivalent to the free quota limit when you are using a key.

To be able to monitor your usage and, if needed, get more quota it would be best for you to start using an API key. You can then check quota and monitor your usage in the Google Developer Console