SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1697ff3f782a568649592e2bb210db7acab33509036da2a1bf22aefeb50c466e' 
  AND token = 'AP7Jc+zZfmaAUB+sZixr9DpHNPb75JXVYgkG9vSTl1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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