SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b83af5c41c4954180643aaa477ad9a18d34d2abd5ee44153197fbc635ad5a60f' 
  AND token = 'IuohNsukao4ixJ786uEnQLOjOdlzmCZURrnC+1UeWLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

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