SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7405521feb49639a18b037f3f2a624b3c84833dd9694b3c0e4e9579394e19aae' 
  AND token = 'Ph7Jd3Ivinn1y16LudNSwDhAwdqmWn92eTwiBguB8Pw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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