Present subjunctive after 'until'?

I consulted https://english.stackexchange.com/a/7823/50720, but when is the present subjunctive (call this PS) used after 'until'? Only in the past?

Am I right in guessing that do here is conjugated in the PS?

1. Till death do us part. => Until death do + part us => Until death do (instead of does) part us.

The present subjunctive was formerly used in clauses beginning with 'until'. It is not so used in modern English. The auxiliary verb 'do' was formerly not uncommon in non-emphatic affirmative present and past simple firms, indicative and subjunctive. It is not so used in modern English.