SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07a31591ade2b84965419722c668a9f49a837eb855b4f6c03bce86de67f9cad3' 
  AND token = 'uPNFZh0U12jPg3/ECT1Tpve+cVVFVdWY+lHRhn+xg7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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