It looks a little complicated in Google Sheets, but the formatting for a query that you could use in the conditional formatting is here: https://infoinspired.com/google-docs/spreadsheet/datetime-in-query-in-google-sheets/
...say the current time is 930am, so the cells that have a time BEFORE 9:30am yesterday should turn red. The cells that have a time AFTER 9:30am yesterday should remain unaffected.
There is a setting to choose so, right from within the conditional format menu.
For your chosen range you pick the
setting Is between and as values =NOW()-2 and =NOW()-1