SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9063231104730572fb905cb80cf347f966226363069d4226bdbd96755c5ac7d' 
  AND token = 'PRzt6lTwMZrHxlGoVILze6SgUt5RtMMVkTTwW33gH0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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