SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e4fd0508617d666f8433fc542600370547d8c9e4445329638b2be69fbea475f' 
  AND token = 'ZWpHyugrNwxh6O2qLG+NJCrKKNlbizx+irCVnUnkrXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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