Here’s the answer for later reference:
In a DataSet
WHERE some.boolean = 'false'
With OQL module as escaped literal
'WHERE some.boolean = ''false'' '
Edit: Seems the solution below didn’t work for OP, didn’t read post fully. It definitely works in current state though!
To follow-up incase anyone else ends up here: It’s a boolean value, you don’t need to compare it to false or true.
If you want it to be true:
WHERE MyBoolean
If you want it to be false:
WHERE NOT MyBoolean
Naming your booleans properly helps this make more sense: “IsValid” is a great name because it reads well.