SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cc267aba6226dcb77bedd60920e58e7c99fdd29bc1acc8be062f48dd27e2f4d' 
  AND token = 'OGING8n97GiGIv55QlJlchaWH80O1hGbaLi3NnT+gYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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