Magnetization, resistivity and 11B, 59Co NMR measurements have been performed on the Pauli paramagnet , and the superconductors La0.9Y0.1Co2B2 (Tc≈4.2 K) and La(Co0.7Fe0.3)2B2 (Tc≈5.8 K). The site selective NMR experiment reveals the multiband nature of the Fermi surface in these systems. The temperature independent Knight shift and 1/T 1 T clearly indicate the absence of correlated low energy magnetic spin-fluctuations in the normal state, which is in contrast to other Fe-based pnictides. The density of states (DOS) of Co 3d electrons has been enhanced in superconducting La0.9Y0.1Co2B2 and La(Co0.7Fe0.3)2B2 with respect to the non superconducting reference compound LaCo2B2. The occurrence of superconductivity is related to the DOS enhancement. © 2016 IOP Publishing Ltd.