SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '78a7011ab57c8bcef2cdda93c98bdf7b7ad5c70b86740bb4b9c1d7599397dff9' 
  AND token = '3saS81EEdmaNLiDJoVTgPpydG2JVF0BCesof8d12jnU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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