Green’s Dictionary of Slang

1. (US) drunk.

1912		R.W. Brown ‘Word-List From Western Indiana’ in DN III:viii 580: keyed to the roof, adj. Very drunk. ‘He was keyed to the roof when I saw him.’.
1936		G. Meek ‘The Favourite’ in Station Days in Maoriland (1952) 65: When the coddled Jack-a-dandies with the best were being keyed, / Harold Logan often wondered if he’d ever get a feed?

2. (US black) intoxicated by a drug.

1972		E. Folb Urban Black Argot 141: Keyed to be ‘high’ on drugs.
1997–2000		College Sl. Research Project (Cal. State Poly. Uni., Pomona) 🌐 Keyed (adj.) Intoxicated; drunk.
2000		Ebonics Primer at www.dolemite.com 🌐 keyed Definition: to be high Example: I am keyed, dog.