Answer
The energy conservation law is violated.
Work Step by Step
The $\Lambda^0$ has energy $1115.6~MeV$
The proton $p$ has energy $938.3~MeV$
The $K^-$ has energy $493.7~MeV$
The net energy on the right side of the proposed decay is $1432~MeV$, which is greater than the energy on the left side of the proposed decay.
Therefore, the energy conservation law is violated.
