SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abc575d15f3cb0da1428634493ef4f3cb9f5bc0266f0d7656a3accac5fd99125' 
  AND token = 'ZYK5aSyGQwgWfO6j8vRvpTNSJySRz/1jxBOIH45svkc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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