SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79734662dbf3433c7f1aa5e2072e2f9bba608684095334ae920f3c45c5992de8' 
  AND token = 'dELQJno9KLqhYq7vID5i1jwAqI7PQpFnRTJ89CCsdxI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

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