SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3920f1fb235c2e627f326bd96ea7a2e118029c4b8a14169271f91a14b866a478' 
  AND token = 'k8UmawdqT1Rxtl3c2Ct/JNx261ZsMdph+/GWAwHs+Y8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

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