  Zero-dimensional dissipative action possesses non-trivial minima known as
Korshunov instantons. They have been known so far only for imaginary time
representation that is limited to equilibrium systems. In this work we
reconstruct and generalise Korshunov instantons using real-time Keldysh
approach. This allows us to formulate the dissipative action theory for generic
non-equilibrium conditions. Possible applications of the theory to transport in
strongly biased quantum dots are discussed..
