Keys in a dream point to access -- to a place, a relationship, an opportunity, or a part of yourself you feel locked out of. Losing your keys usually reflects a fear of losing control or missing a chance, while finding an unfamiliar key can suggest an opportunity you haven't recognized yet.
The qualities of Saturn and Mars are not made better by their Conjunction; being mixed so together, they are confounded, and hurt very much. - William Lilly (1602.-1681.)