SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3c49db339c293e54d45410e3eef01a578a230cde50b8f1db4b918bf73cc24fc' 
  AND token = 'NEr/8pjbOfrRjC7jTGClJ5iD9DqT6VvKx4Q2W328wOo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

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