SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '195c8d368d32b38df21a7fefc4bd0e1393e3df45121d34ebd919364e458df5b8' 
  AND token = 'xzP7sIiK0wwQQaEnhupR2ijgc/vZUDEgvFhn8VH1+gY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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