SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8663f7c3dffd7d6516de3db5b6ca03a5c6dc2ab9ebd691cbcea8d157ca6688f6' 
  AND token = 'l4juruNsusko210GrWlldsDZlmlep5Eejv4fFtbWjGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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