SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b64eae722d0e3210b014fb23abe43fd91855950e0bfb8c79f984771c53204fb' 
  AND token = 'zlMwUbIzeHLQ1eJ+Ucev0M6VGJC+9vJL9E52koBiU6A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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