SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae75d8d643a6cc9b9f84a610474d3f94de2973880598828d9bd55d49344e2b30' 
  AND token = 'rAtHVT6XN5HSHmpZ/nZ1zIuc6MxV/S3i9PO3PT9xXZ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

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