SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cbc658a26747d4978a2f543ec273c86298a47d798413b21291638d5e9913110' 
  AND token = 'YxhawdVNtXvKSOivfHnf++esXsLe0sUCtjiUdxIiOSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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