SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34374b55dfe42e9ab3fce93f5ed8f0e7d0071905cb153c25de454f172407bbed' 
  AND token = 'egs/htpr8O2Ruful6+wNlFJHBU+VaQXgfNHAxuHj8jk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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