SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7312fa049ba2d47f3312890aaa395d262f575303c29e5e41cd4695c1d879cc07' 
  AND token = 'GNYJOqVbJGh9I62/9ltGLYvM3tgFnfeVzbsKXvuxVsk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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