Update query for Member.with_elevated_guests

The following discussion from !140759 (merged) should be addressed:

• @bwill started a discussion: (+1 comment)

  Question: Was the index coverage verified? In the database review evidence, I only see information regarding the migrations.

  Thought (non-blocking): I wonder if this test could be improved by checking columns against the available indices similar to this code. I think this might be difficult due to the complexity of the query.