SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e3d6c37fa82d2ae9a115fd16153b431e2ac67481fc9fa4be1d45934b699b584' 
  AND token = 'WUwiwYgqHBAUDkXNLOtz+pkYOTDMpaLd96B7yRpldYU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}