SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e4ff68509a172fc3e9c08bd28339e92b719a9c2099c25a845a3dc8cae7439bf' 
  AND token = 'Tz7bUpMS1i4gB8VDU8wgSxUsW5svTMvYDPS6foIEe2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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