This paper presents a low-order spatial discretization to solve the Maxwell equations in the time-domain, namely: the Compatible Discrete Operator scheme. The basics to build this scheme are recalled, and it is shown how this scheme allows to efficiently deal with hybrid meshes composed of a Cartesian part and a simplicial part, with polyhedra at the interface between the two. The scheme is formulated for the Maxwell equations in the case where the computational domain is surrounded by Perfectly Matched Layers. Finally, the paper proposes some numerical examples on meshes with non-conformities, to emphasize the robustness and the interest of such a scheme.