If you need to find something quickly, PhotoStructure will scale to that quantity, and if you've got exif or sidecars with keywords, those tags would be navigab

If you need to find something quickly, PhotoStructure will scale to that quantity, and if you've got exif or sidecars with keywords, those tags would be navigable as well. There's a pulldown that then let's you open the enclosing folder with the current image selected. You can also do performant SQL queries on path, keyword, or a bunch of other metadata attributes. Disclaimer: I'm the author.