Make targeted query to a specific shard without using the shard key as part of query.

As of right now you need to use the shard key as part of the query to make a target query to a specific shard. Would like the ability to make targeted query to a specific shard without using the shard key as a part of the query. Maybe one way of doing this is using index metadata to avoid scatter gather query and using that index meta data to instead make targeted queries on sharded clusters.