SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4497ddfbe929450043638f8e2b525929ca12035c2dd2f65d9aab20b68f75f87d' 
  AND token = '7JRnQBgHmcXF8qdJym5GWrsuw/Al2AIVa0RrSCjh29o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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