SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a865495c891fda861f2588405bf25c9a7da4bf437b81fd5a54bbb04afccb786d' 
  AND token = 'voYXQPRT6ZaroGSJi1IahmAsLr5GxaPxdOjIkHMnZps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00067

JSON explain

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