Indoor cats are less likely to get infected with toxoplasmosis than outdoor cats.
Cats usually become infected with toxoplasmosis when they feed off of other animals that they catch in the outside world and then eat the raw meat from those dead animals.
Cats that are mostly indoor cats or full time indoor cats should not get toxoplasmosis unless they happen to eat some raw meat.
So as long as you keep an eye on your cat and not let the cat outside or around stray cats then the cat should not develop toxoplasmosis.