SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c3cd78d9799b842df674c8b3e5fe8bb0f12bd3c301b9027a5268995afa31e81b' 
  AND token = 'xzifqn8vHahSZQM0qlqISyaYphX/cEgZmqbk36dsgVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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