SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba8b1d84ec64f8477b2f590d8df88ab17be42170ab763721b85432d7fb5da143' 
  AND token = 'UVZwO0I72cdZG6GpmmHWjRuYz3TF4SvdHR+qpgDB8QM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

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