SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6745fc05e8b2af492382f4211df6d91e9bcb9a9bc4605f2ba2a3144156f35e77' 
  AND token = 'oZJ3HbH1Y7Lu/aCZJNQcY/FOUas3cZhH5hdj8eHi3tY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}