SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '327ab9535bf3b4fa120f4af5ee7d762f2ea255336368378350e7d339ba197136' 
  AND token = '3HjVBCKvZ9lRiZwGmeBim4HvIKSrI7DH9Qsbt/hOOPg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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