Since the "Bone IK Chain Constraint" is such an important "Constraint", it has its own shortcut "Shift + I" which is quicker than the normal way of adding a "Constraint" with "CTRL + Shift + C" and then selecting for example "Inverse Kinematics" as "Constraint":
You just need to confirm "Add IK" => "To Active Bone" instead of searching in a long "Constraint List" for the "Inverse Kinematics Constraint".