SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '6d0e3211949b08ec3738989cf4817ad63028440ac32b11e3e8559f923562e52d' 
  AND token = 'sFNhv/+1Cq2ILNHDlQSvBU+8XtZEr2ZHXAQXQ04TRpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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