A person who was an active member of a fire department covered by either the lump-sum division or the monthly benefit division of the plan who has separated from active firefighting service for at least 30 days and who has completed at least five years of service credit, but has not attained the age of 50 years, is entitled to a deferred service pension on or after attaining the age of 50 years and applying in a manner specified by the executive director for the service pension. The service pension payable is the nonforfeitable percentage of the service pension under section 353G.09, subdivision 2, and is payable without any interest on or increase in the service pension over the period of deferral.