SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99680919224b8a4a6e06202ffa196ed4be6fa1816e5c6f372b4bce1be26248bc' 
  AND token = 'WO+O4x3xlUShQKjh1CFWL3LsguGAkQpP+PrIKtcY5uE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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