How to get document by id (Get API) on a time series multi indexes environment?

Unfortunately this API is not supported by the Java client. I probably need to use the ClusterStateRequest as explained in this discussion.

Somehow I feel this is getting over complicated.
Doing a realtime lookup for a unique id across multiple indices (time series) sounds like a common use case.

Am I miss using Elasticsearch or is my set-up wrong? Is there a better way than getting all indices names and running a Multi Get to achieve this?