SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd23e28f8a3e2be41af480c28edcbfa62899f2f107e3caa8fb2d22799abe52462' 
  AND token = 'M/9AkNKXZK+30F2tE7cAULcvNvTGDQxQrBNgGBfQheo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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