Reactive is not necessary at all. Once you had moved the site, you need to de-activate and re-activate the plugin. This forces the plugin to re-write the css path as new site url.
However, in your case you have already deleted the font and deactivated the key. You were using the Test API key and it gets deleted once it is deactivated. So if you need to use 1 font, please kindly re-generate another Test API key and use it.