SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8489d56c2393eb5d20f23274a61ad485b7ff8e79ee9b15349512ead70db848ad' 
  AND token = 'dMN+Hu+3JcxUkDdMxl1iosahMuh8f25DCEmJgFSLCyM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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