SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b3d74ce5fcdbd2c347b2e8a84dbd0511ac6e3fadc16d6dd1d7fdb2559b1d0acf' 
  AND token = 'iXX9zRx+MH/UYI5GDyhmjqRzfUd1LGXR6GAChtOLtzk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}