Don't you have those fast tests?
Over here there are pop in "test huts" outside shopping centers where you can just pop in and take a test, answer in 15 minutes.
No way to test for antibodies the fast way, yet.
Still the old fashioned lab blood serology.
Maybe you were meaning antigens (for testing current infection).
Not sure what they are testing actually, some signs just say "covid 19 test" others say "test if you have had covid 19" but that could just be to lure you in. I might stop by one today and ask.