SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac4080566a2a86ba357c475b902affe692f8866f5036c028654462d5f945f200' 
  AND token = 'KhmdxAD3dSeI3R4xeolMOnwUXVAk7c0afZbckztX7iE=' 
  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