SQLite can be built with the R*tree module, which supports efficiently looking up all bounding boxes that contain a point: https://www.sqlite.org/rtree.html
PostGIS similarly provides an R*Tree index mode, as well as a heap of functions for doing GIS calculations directly. To do that in SQLite, you'd implement and inject custom functions as appropriate.
Does SQLite have GIS capabilities (like PostGIS provides for Postgres), or is this storing the data as traditional database primitives?
Check out Spatialite. https://www.gaia-gis.it/fossil/libspatialite/index
SQLite can be built with the R*tree module, which supports efficiently looking up all bounding boxes that contain a point: https://www.sqlite.org/rtree.html
PostGIS similarly provides an R*Tree index mode, as well as a heap of functions for doing GIS calculations directly. To do that in SQLite, you'd implement and inject custom functions as appropriate.
DuckDB has put some effort into GIS, so if SQLite does not immediately fit the bill, I would go there.
https://motherduck.com/blog/getting-started-gis-duckdb/