SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c2edff831510a98db4b0010e8a84ab1d1bdb6f5e7b3f208410a3793e03dcbee' 
  AND token = 'ntznPYPrP8Zu67MNozNd3mrMiznJPP6AGZZsx1G+V9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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