SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '39d4cab675d83d11774659690680c1668fc4a77c7da45fbd24617655d4df42c0' 
  AND token = 'xooFbuNsCym+K9m+8ABEgTCqjmlU/YtM2HcPaPW2XtA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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