SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '927991c59a5c4b7aadb0e6d70b6d85bbd38da43d716cb410ecd3a6a2bd293f71' 
  AND token = 'h23xCCRqCCdsMCWIXsKMmi9yTk4y/rfnSgQb/yZWAG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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