SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1c318bae84d782c57d63e241d5b88347343f2b823c664a57176c118b8521cf35' 
  AND token = 'U8uw37U6yiHDHgV6k8+/DLA6I9IIQyeErWyk08SxvH8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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