SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b48dd1f789c4e605d42ddac3fd4812b5ddf625541eede074de3bc789a2f8767' 
  AND token = 'Dph+pbjwJ9nEy1ZHRGf7OJLx5AUBeaR7kyXqKypXmfI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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