I haven't tried this solution yet but it was mentioned on another forum here.
If you go to Mustek's download page and search for your scanner, they should have a download called ScanMust that's made for Catalina (MacOS 10.15)
I'm still on Mojave so I haven't tried it yet. Let me know if it works, and good luck!
EDIT: I have the SE A3 USB 1200 Pro (Which I find many comic artists also have) and it DOES NOT work with ScanMust. Unfortunately.