SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b71880e0730861e5735f9ba232db3c6acacd51888a57a09c3219662209780f3' 
  AND token = '2h4zVTd9cJRr3K6o6nKp5Mofp+7PXNkndNcLdpUvzHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

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