SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3d3d0a47486018e2e3360fec10f4da0a49315ca08fc9eeb8a0a387ca596a6820' 
  AND token = 'jQXmsfPWaMT37tpExKtJytz0OTwipIst9ZDnsSNjKQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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