SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c08c11b9444f85a43456689d868b00dd7a3ac11dd8e072f9274b23d8c44d7fb8' 
  AND token = '1oWp/FBqEIl3XMQ7UxZll7Y9rOt8dhM8c+tnbgGQrWc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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