This is the sql I used to get reactions on SimpleX. Everyone should be able to find out who's reacting to stuff since reactions are sometimes abused on SimpleX and they're accessible via the database anyway.
I think the easiest way is to use the cli version because the database isn't encrypted and the cli database is different from the desktop client's by default. Here's the link for instructions on how to use the cli: https://simplex.chat/docs/cli.html
I wouldn't recommend messing around with your real client's database even if you only plan on doing SELECT statements, but you can. Instructions on how to use sqlcipher to open an encrypted database