File cache store doesn't check if file exists if prescan is enabled

        if ($this->prescan && array_key_exists($key, $this->keys)) {

            if (!$ttl || $this->keys[$filename] >= $maxtime && file_exists($file)) {

                $readfile = true;

            } else {

                $this->delete($key);

            }

if (!$ttl || $this->keys[$filename] >= $maxtime && file_exists($file)) {

// Without parentheses.

php > var_dump((true || false && false));

bool(true)

// With parentheses.

php > var_dump(((true || false) && false));

bool(false)