SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae3014c60056a151495497247e8dc5c6979aedd6991cf5185944ff08362add7c' 
  AND token = '4+I5UWZd0NmFuTAFqAFcnppIDZ6JQSKqdK6Vcyz2Voc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

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