SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '614c80b52f949f1f3e5162d0d40c36b9b51317843876384f739e42e9e34ee7d5' 
  AND token = 'ikTFUl3jIVZ9Lg299KU//vtgZpor2UBTXnxa6KZ7glI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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