  Antiferromagnetic van der Waals family $\rm \textit{M}P\textit{X}_{3}\
(M=Fe,\ Mn,\ Co,\text{ and}\ Ni; X=S\text{ and}\ Se)$ have attracted
significant research attention due to the possibility of realizing long-range
magnetic order down to the monolayer limit. Here, we perform inelastic neutron
scattering measurements on single crystal samples of MnPSe$_3$, a member of the
$\rm \textit{M}P\textit{X}_{3}$ family, to study the spin dynamics and
determine the effective spin model. The excited magnon bands are well
characterized by a spin model, which includes a Heisenberg term with three
intraplane exchange parameters ($J_{1}=-0.73$~meV, $J_{2}=-0.014$~meV,
$J_{3}=-0.43$~meV) and one interplane parameter ($J_{c}=-0.054$~meV), and an
easy-plane single-ion anisotropy term ($D=-0.035$~meV). Additionally, we
observe the intersection of the magnon and phonon bands but no anomalous
spectral features induced by the formation of magnon-phonon hybrid excitations
at the intersecting region. We discuss possible reasons for the absence of such
hybrid excitations in MnPSe$_3$.
