[As per suggestion of user151413, comment converted into response]

A few sanity checks to run:

 1. Ask them who else is in your session and with which topics, if possible. 

 2. Check the participant list or the confirmed speakers. I know established researchers that had been taken in by junk conferences. If a junk conference manages to get a lot of good speakers, though, it ceases to be a junk conference :-) Of course, they may lie, but that is usually less likely. If you know one of the other invitees, you could pop them a mail and ask them whether they go.

 3. Check the topics. Does this look like there is a proper scientific agenda or just a jumble of buzzwords? Are the sessions organized by topic (more or less)?

 4. Is there a program committee? Do you know anyone on this list (even just as an author, not personally)? 

 5. Unfortunately, the often-cited killer criterion whether the conference is at an attractive place does not mean anything. Also good conferences like attractive locations. However, if the conference is running at a nice location while a pandemic situation is still going on, this is most definitely a red flag.

Good luck!