SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6db07c347e136cab8e9bcf058f10b5199edfbf95e99c4d619479ffd0b3d2ad15' 
  AND token = 'KMyWGV+GtHDlJocnsTuqdW2q0zQfaNxb5zGRvp3QFE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

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