Searching with indices hint does not perform better

It seems that providing a set of indices when performing a search using the Java Client does not perform better than without that hint.

For example:
elasticSearchClient .prepareSearch("index-1", "index-2", "index3") .setIndicesOptions(IndicesOptions.lenientExpandOpen()) .setQuery(...) .setTypes(...) .setExplain(false) .get()

elasticSearchClient .prepareSearch() .setQuery(...) .setTypes(...) .setExplain(false) .get()

The second query performs way better (e.g. takes less time) than the first one.

Have you ever come across a similar situation?

ES Version: 2.3.3