scantxoutset

You can run a pruned node on your machine locally and scan for UTXO's for ANY address (doesn't have to be imported to your wallet) by using the scantxoutset command. It takes a few minutes, but not nearly as long as a rescan. Doesn't take up a ton of space, and better than using a blockexplorer.

To query one address: scantxoutset start '[{"desc":"addr(1SomeAddress)"}]'
Or for multiple addresses: scantxoutset start '[{"desc":"addr(1SomeAddress)"},{"desc":"addr(1AnotherAddressToCheck)"}]'