SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd961ab18e9114fe62f83f1810d70dadffdea6ae7357dcc0626364dec44c81cb4' 
  AND token = 'N8Kr9f6ZEWW7IXExowjqJ+CJj8sTWf8a+vRF2q84/yU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}