SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9b86cc333fe6516bc217a5ae5de0d1e9a96f9b107bc568cbda332d8902b95ec' 
  AND token = 'di13SBppq79KgWol95hv/9HP6NhVTeVIzQMqZs6oZO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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