SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e43344d67029dd81bc836ffbc125e778ef3b1303316822385c0ae0c29c8c45f' 
  AND token = 'YT/NmEj6g1GMcrUdJJwoEkjU5whVRBL5hWz1/9Tfehw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

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