Yes, CHOKING is a Scrabble word!

Letter values in Scrabble US: C 3, H 4, O 1, K 5, I 1, N 1, G 2.

Is it a valid word?

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

a condition caused by blocking the airways to the lungs (as with food or swelling of the larynx)
the act of suffocating (someone) by constricting the windpipe

breathe with great difficulty, as when experiencing a strong emotion
be too tight; rub or press
wring the neck of
constrict (someone's) throat and keep from breathing
struggle for breath; have insufficient oxygen intake
fail to perform adequately due to tension or agitation
check or slow down the action or effect of
become or cause to become obstructed
impair the respiration of or obstruct the air passage of
become stultified, suppressed, or stifled
suppress the development, creativity, or imagination of
pass from physical life and lose all bodily attributes and functions necessary to sustain life
reduce the air supply
cause to retch or choke

Also: choke off, clog up, back up, pass away, kick the bucket, cash in one's chips, buy the farm, give-up the ghost, drop dead, pop off, snuff it.