Green’s Dictionary of Slang

(US) fine, excellent.

1956		E.J. Ruppelt Report on UFOs 122: Our vast files of reports are in tip-top shape; and in general things are hunky-dunky.
1981		oral communication in Lighter HDAS II 202/2: Now everything looks hunky-dunky.
2002		NEP HoldtheFrontPage.co.uk 🌐 Checks by the HoldTheFrontPage team have proved beyond reasonable doubt that the following phrases have all been uttered by one person. [...] ‘Everything is hunky dunky.’.