SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd70b3b5cb419661782c2a3f3707f081b127621b642bf8420534aae628ccf0c81' 
  AND token = 'jUDek7vwhMMHrjGfYcQz+iTLBKZVgG0xi0wHq4IrlMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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