SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'bde406dcc763ed9696c21b0902ea0fa69a2ad8aa7559e9754fe91239740a90c0' 
  AND token = 'QOM4k2qPTxrcybvS8uj066xGu0fjNd0Wt7UDlIkXcy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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