SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8ef42e85ac98e10f8c94ba72b7d59b3e1108564c14c2bfe12452bbfb209fc4c6' 
  AND token = 'NkrtmDwWpUp5/3VhcooYOcBI6jqRVikTJXH6lCqDc+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00067

JSON explain

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