BUG: parsed datetime string resolution incorrect
I was working today with datetime index, you have the reso (resolutions) defined from year to nanosecond, but then you had the lines 560-570 repeating 'minute' and 'second', and working with millisecond or nanosecond raises a KeyIndex error.


- [ ] closes #38121
- [ ] closes #38077 
- [ ]  tests added / passed
- [ ] passes `black pandas`
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ ] whatsnew entry
