SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e1b601dba70a44ad75f26a47d7dcc26200199fceffad5d1b757d92696b3b819' 
  AND token = 'qt2tMtHtK9mS9uP1KlHsmyLg6ote4DEDDBOMkqVtVUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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