SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd34a73ae36f75716c80cf8fc57ff9c3af0f1a1e92e7619a4457414171b8fc067' 
  AND token = 'Mmjj80H+wYIBfz/2NhUBJtrq7WcEIWqSKOxDGi7UzVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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