SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ad4459cfbf2f6b2b0861f98598206ffe542771796216c0f83cfda6f01e93a5a' 
  AND token = 'CnzQ+MQRSsIaGqUFYBbCbF2eoP+hUAzwUT3Rrey/NoY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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