SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2946d79be95fe544246c60a8c5915c3e3f86ee871424322ed66f12cbb8b026af' 
  AND token = 'vIzEYNbqfBnsE2cnJb7VLHVJxRmbgNMcRGKp5fMVwDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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