  The emergence of zero energy states in non-topological superconductors
represents an inevitable problem that obscures the proper identification of
zero energy Majorana bound states (MBSs) and prevents their use as
topologically protected qubits. In this Research Letter we investigate long
superconductor-normal-superconductor junctions where trivial zero energy
states, robust over a large range of parameters, appear as a result of helicity
and confinement in the normal region. We demonstrate that both equilibrium
supercurrents and critical currents are sensitive to variations in the length
of the superconductor regions in the topological phase hosting MBSs, but,
remarkably, no such length dependence exists when robust, but trivial, zero
energy states are present. This strikingly different response originates from
the non-local nature of the MBSs and we, therefore, propose it as a simple
protocol for distinguishing between trivial and topological zero energy states.
