SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f33e2b6344db1c88ce7b882da62863ea596395e8f644ff5cbf4ccb505ba900f4' 
  AND token = 'KVXAMb/3Sc9IpVKlnzK9uGh/Y4Mn8v5pxK3s8zs7FPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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