Check if KeyValuePair exists with LINQ’s FirstOrDefault

If you just care about existence, you could use ContainsValue(0) or Any(p => p.Value == 0) instead? Searching by value is unusual for a Dictionary<,>; if you were searching by key, you could use TryGetValue.

One other approach:

var record = data.Where(p => p.Value == 1)
     .Select(p => new { Key = p.Key, Value = p.Value })
     .FirstOrDefault();

This returns a class – so will be null if not found.