Back when I handled a journal, the most common method I used to find reviewers was to search Web of Science for related articles and invite the authors of those articles. Any submission to the journal will include an abstract, possibly keywords. Those keywords enable a Web of Science search for related articles, and as a bonus those related articles usually come with the contact information of their corresponding authors.
One of the upsides to doing it this way is that you avoid having to invite author-suggested reviewers (c.f. potential bias), although sometimes an author-suggested reviewer will show up in the Web of Science search anyway (which is a sign that the method is working!). Another upside is that Web of Science has some analytics tools to see which authors are writing the most articles, who is citing who, and so on. A third upside is that you typically end up with so many potential reviewers that you never overload or overuse any of them.
Downsides are sometimes you end up reaching people who, like you, may no longer be in the field or may no longer be research-active. It's possible to find things like this out by Google, but it's time-consuming especially if the name is common (especially the case for 2-character Chinese names). For the same reason it's possible to reach people who might not be very experienced in the field even though they've written a few articles in it.
In your case the invitation reached your work email that's not related to the published article. That makes it more likely it's a recommendation as opposed to a direct search. It could, for example, be that the original reviewer they invited declined, and recommended you. Still, possibilities abound; it's not possible to eliminate all the alternatives.
Edit: About this -
In addition, the email came to my work email, but it is not associated with the published article, and I did not have an account with them.
It's possible another reviewer declined and suggested you, using that email address. It's also possible they identified you as a reviewer, and then Googled for your email address.