Cache expiration does not work with posting queries

[ghost]

If I use a query instead of an execution id and set a cache duration on that query, it never updates after the first run, even well after the result should have expired. The only way to cause the query to re-run on fresh data is to restart grafana entirely.

My best guess is it is because the cache key is based on the execution id, which does not exist for queries (at least not until they are run, but to re-run a query you wouldn't want an old execution id anyway).

[djesionek]

I noticed the same problem, would be good to have that fixed.