> What if they were conscious?

Well, they're not.

> If they aren’t but still a lifeform, that makes it perfectly okay?

According to Jains: No. Violence against plants, insects, and possibly even certain microorganisms is considered unethical.

IMO as an irreligious person: Yes. Life is just a particular form of self-sustaining and self-propagating system. Those properties are of little to no moral value.