SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6319531aef28d7e139ceb3682b7cf730e77596aad3a8faab15c2ca7005df544' 
  AND token = 'ARKuyOLX+uNpM/ZoqEsTLf8lEkYFgyPDlQU8LJWpVSw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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