Yes, BEMUSED is a Scrabble word!

Letter values in Scrabble US: B 3, E 1, M 3, U 1, S 1, E 1, D 2.

Is it a valid word?

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

deeply absorbed in thought
perplexed by many conflicting situations or statements; filled with bewilderment

Also: deep in thought, mixed-up, at sea.