SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a3c540ddfc2d6ea3273a24e21b74fbdc18d2deb27e04bf726d43d44167f5d8e' 
  AND token = 'yyr/tmcEDnclXJK8FIN36Jvf+tofORO6kWrcGoEQpKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}