Identifying issues in cache lifetime verification implementation

In the provided PHP code fragment, a cache lifetime check is implemented. It is necessary to analyze and point out the shortcomings of this approach, especially under conditions of handling a large number of requests simultaneously.

$cachedTime = $memCache->get("time_$key");

if ($cachedTime < time()) {
    // update cache
    return $data;
} else {
    return $data;
}

Pay attention to possible race conditions, redundant cache accesses, and other issues that may arise during parallel operation.