The show ran from 1991-1999.

The internet went public in 1992.

imdb was on the internet in 1993.

Other search engines existed before Google. So while it’s true nobody could google anything before 1998, it was possible to google the actor before the show ended its series.

I don’t recall IMDB being particularly good with TV shows until the 2010’s, though.
It was merely one example. I’m sure that was the only site anyone could use to look up what actors looked like.