Yes, FOCUSED is a Scrabble word!

Letter values in Scrabble US: F 4, O 1, C 3, U 1, S 1, E 1, D 2.

Is it a valid word?

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

direct one's attention on something
cause to converge on or toward a central point
bring into focus or alignment; to converge or cause to converge; of ideas or emotions
become focussed or come into focus
put (an image) into focus; we cannot enjoy the movie"

being in focus or brought into focus
(of light rays) converging on a point
of an optical system (e.g. eye or opera glasses) adjusted to produce a clear image

Not playable in Scrabble US: CONCENTRE.