SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f99f75cc3e255a7a69505ab3dc86d1928abe0f67a962d03521c2e326c8d964d' 
  AND token = 'PzmWLr5GoBgzKAF3ErvLydTHh9naYwMiZT/kBFZ4FkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00110

JSON explain

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