SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '950fd7777f3b0c85217098cd4e297fdcaf73ac14d1fb45f6d1648f4b399a4fc6' 
  AND token = 'g5aUmjSJ1WZaN30/wZPRUKxowBrPoxnx8nxLOaBt/aU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

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