I certainly agree with what James is saying, but if you're asking how to first check to see if a record is locked, try updating the record, replacing a field with it's original value such as:

UPDATE names
SET names.first = names.first
WHERE names.keyid = "001"

If you're using pessimistic row locking and the update is successful, then you've just locked it and it's available for updating. Query the data for the fields you need and edit them as desired.

Hope this helps.