SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96897d8e29ab553dd8b0e0f611123d0463e7a4b7612f073f753ab05cf28888de' 
  AND token = 'nDufwmagDoug7nbO0qE23BqHqWOb6RJeD9icihAec/c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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