SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00ae50712f93e2596409ea87f82f6b5ae5b007d76c64c4bd5a4cd880830b6c17' 
  AND token = '0WsxyFFwjAj8uGzN73VNWIbBZSRuJm+njqVhXIUTwzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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