Improving query access performance for unordered maps that are unchanging

I am looking for suggestions in improving the query time access for unordered maps. My code essentially just consists of 2 steps. In the first step, I populate the unordered map. After the first step, no more entries are ever added to the map. In the second step, the unordered map is only queried. Since the map is essentially unchanging, is there something that can be done to speed up the query time? For instance, does stl provide any function that can adjust the internal allocations in the map to improve query time access?