I've recently presented the approach with exhaustive search and heap, then iteratively adding simple indices, using ClickHouse. It works pretty well despite the overall usage simplicity.
Video: https://www.youtube.com/watch?v=hGRNcftpqAk
Presentation: https://presentations.clickhouse.com/meetup74/ai/
PS. It should work at the same speed as "bruteforce-blas" in the ANN benchmarks.