Try free [Search by Image][1] browser-based OS-independent tool (Windows, Linux, Mac etc.), which I developed. The limitation is the browser type (works best for Chrome and Firefox, some browsers do not support folder selection or too slow parsing the file directory), the file read speed, type of images (browser-readable only), and available memory. But if you have a good PC, I would say it is possible to scan 50000-100000 images without a problem.

  [1]: https://similar.pictures/similar-image-search.html