SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79b1b330478196895e67f847fcbffc8f36cc4fc9be9fd249877a7249a1cda22a' 
  AND token = 'nZbTg+TpGLp+k6QsyU8yxs8DcjhtWiBrVTP8HBQ52ro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

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