SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0252be4f06af97e25f10947bb10f0a84652f1f98026fa4adf687f6793fd99c12' 
  AND token = 'KIn8TogPPYBKj6CVUePn9GxQTt97xg+ONl1rJHna1GM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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