SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0becc5bb25d4ac8a7d74b40da320874a58bf63313f528ee77fc865fdfacd397' 
  AND token = 'xnKixwTa/9Fo6HtMjLb6W203M78GzYxmJh/08/+wg/A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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