SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98ec487f0afdfec7cbfce9ed9aa24603747ec83baa748648214ff69f93977221' 
  AND token = 'kNvY74QmjLyKjBl888AroIcZlOMUmMqKFNCNOypcEaI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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