In a large mixing bowl, combine the thawed corn, cherry tomatoes, cucumber, red onion, and feta cheese.
In a separate small bowl, whisk together the mayonnaise, sour cream, apple cider vinegar, garlic powder, onion powder, salt, and pepper until smooth.
Pour the dressing over the corn mixture and gently toss until everything is well coated.
If using, fold in the chopped cilantro for added flavor.
Cover the salad and refrigerate for at least 30 minutes to allow the flavors to meld.
Serve chilled or at room temperature.