SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42716826aa6384c9560a59e8302cc85667b073cddcc8fa8c1c2b5b7924c24fa8' 
  AND token = 'NKWvyeLipEWcAqNombN7k7tvxgV/d8vNgpFkf8dDPvA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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