SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5faf2c0d9722af17ff9b1643c47346229eb4be6753968ec6dbea4da1802c3573' 
  AND token = 'KhwsonN97EglGNlg08eNIOVXjkpiyFxPWs/ocMjtiSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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