SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c96df2daa578fbb5b90667ac8ea7dd006c06ba6ba6538ac98edc8f7bd5a7497' 
  AND token = 'Hc2kiEyuMxNinKOgUEX2cIj+PZQQa9v/aR2CfbukIpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

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