SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67c48d299ce8515ec9c472c30747307f1656d98ff74b250d824ea20affbcac60' 
  AND token = '0xwETjlMvherZoGgPog5QwgMqDR0caFX0UvpN4WMzTM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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