Typically you try and avoid closing a connection on each request, you hand it back to a connection pool. The underlying session stays open and associated with the connection (if you have your pooler set up right), so subsequent requests still use the cache.

I agree with the original commenter about ANY as well: using IN for dynamic lists of parameters makes viewing useful information in e.g pg_stat_statements impossible, though it's possible there's been some recent work around normalizing these.