SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c4d6a1fd4644700a45e59e58a55778368d9c0ebca0398b7ff88145a79f0be34' 
  AND token = 'C7RG/P5XFi5h30SqmcBdGjMlWI033vcMx7AlbMDeJCk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

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