Will it still be OK to use my toaster after it got covered in brick dust?

You can clean the dust out. Toasters usually can be disassembled easily. Use one of those air cans to clean and a damp cloth. Let dry. Use a few times before eating toast.

Another idea: toasters are cheap. Get a good new one for $10-$15.

Wipe it off.

press it without any toast/bread in it, and let it go through its full cycle.

If it's fine, nothing should happen.

You MIGHT smell burning brick dust, but running it once without toast should burn that away.

If the toaster operates incorrect, or doesn't work at all, then you have a problem.

The dust shouldn't be an issue in itself. It can easily be turned over and shaken lightly to empty it of any dust.

Yes, just blow all the dust out of the inside of the toaster, wipe it off, and it will be fine.

turn it over and knock the dust out of it, it will be fine! stop trying to rip off the plumber!

Brick dust does not conduct electricity if that is your concern.