That's about as good as you're going to get in a single query.
If you weren't using LIKE, you might get better index performance by unioning two separate select statements.
But I also have to wonder about your logic. If both parameters are supplied, you still want to do an OR filter rather than AND? Normally if two parameters are supplied it is expected that BOTH must be satisfied.
And if only one parameter is supplied, you'd be better off with two separate statements.
If it's not practically useful, then it's practically useless.