SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f3074000d360583e720894edcb5c5a4d1420d36f14e620072783b05a897fb7d1' 
  AND token = 'guAVN1cPVSDni8R8r3UJt0iuNKEAbXCCfYnlpXnZi3k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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