//$array
Array
(
    [0] => O:21:"CalcCalc":22:{s:3:"qok";...
    [1] => O:21:"CalcCalc":22:{s:3:"qok";...
    [2] => O:21:"CalcCalc":22:{s:3:"qok";...
)

$resultingJSON = '[' . implode(',', MAGIC_UNSERIALIZE_EACH($selections)). ']';