We apply the geometrical supervariable approach to derive the appropriate quantum Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST symmetries for the toy model of a free scalar relativistic particle by exploiting the classical reparameterization symmetry of this theory. The supervariable approach leads to the derivation of an (anti-)BRST invariant Curci-Ferrari (CF)-type restriction which is the hallmark of a quantum theory (discussed within the framework of BRST formalism). We derive the conserved and offshell nilpotent (anti-)BRST charges and prove their absolute anticommutativity property by using the virtues of CF-type restriction of our present theory. We establish the sanctity of the existence of CF-type restriction (i) by considering the (anti-)BRST symmetries for the coupled (but equivalent) Lagrangians, and (ii) by proving the symmetry invariance of the Lagrangians within the framework of supervariable approach. We capture the off-shell nilpotency and absolute anticommutativity of the conserved (anti-)BRST charges within the framework of (anti-)chiral supervariable approach (ACSA) to BRST formalism. One of the novel observations of our present endeavor is the derivation of CF-type restriction by using the modified Bonora-Tonin (BT) supervariable approach (while deriving the (anti-)BRST symmetries for the target spacetime and/or momenta variables) and by symmetry considerations of the Lagrangians of the theory. The rest of the (anti-)BRST symmetries for the other variables of our theory are derived by using the ACSA to BRST formalism.