Whenever any municipality has established pension plans for the pensioning of the salaried employees of such city and the surviving spouses and minor children of deceased employees, the right of any person to a benefit, any other right accrued or accruing to any person under the provisions of such pension plan and the funds created under such pension plan are exempt from any tax of the state of Missouri and are not subject to execution, garnishment, attachment or any other process whatsoever and are unassignable unless specifically so provided in such plan.
§ 71.207, RSMo