SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe204f4e7879231646f92ffc4a62dbd3c9529ebbb4320edba0cba17056d76c62' 
  AND token = 's+d0ug5//CbF59YBQJSLGt156JfKnvckaAJV+LZZ6cQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Impossible WHERE noticed after reading const tables