Yes, KISSED is a Scrabble word!

Letter values in Scrabble US: K 5, I 1, S 1, S 1, E 1, D 2.

Is it a valid word?

KISSED is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

touch with the lips or press the lips (against someone's mouth or other body part) as an expression of love, greeting, etc.
touch lightly or gently