Yes, SOJA is a Scrabble word!

Letter values in Scrabble US: S 1, O 1, J 8, A 1.

Is it a valid word?

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

erect bushy hairy annual herb having trifoliate leaves and purple to pink flowers; extensively cultivated for food and forage and soil improvement but especially for its nutritious oil-rich seeds; native to Asia

Also: soya bean, soybean plant, soja bean, glycine max.