SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd04281a640d308f2b733b391ff7eab55234849ea94ec21b98d88f91232756310' 
  AND token = 'qbjV9mC9IKrMWweJmmkmI6qX2LNmncCPDjVeKB+vUTo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

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