A search for the critical behavior of strongly interacting matter was done by studying the event-by-event fluctuations of multiplicity and transverse momentum of charged hadrons produced in inelastic p+p collisions and central Be+Be and Ar+Sc collisions at the NA61/SHINE experiment. Results for energy dependence of the scaled variance of the multiplicity distribution and for two families of strongly intensive measures of multiplicity and transverse momentum fluctuations Delta[P-T, N] and Sigma[P-T, N] were presented. The study was performed in rapidity-integrated way and for different pseudorapidity regions, which corresponds to changing the rapidity averaged baryo-chemical potential and the value of temperature at the freeze-out stage. The strongly intensive measure Sigma[N-F, N-B], evaluated in rapidity separated windows, was used in the analysis of short- and long-range multiplicity correlations and is considered to be sensitive for the initial conditions of particle production such as string fragmentation and fusion.