SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '249a85691783f6756953ca9beab1c29960c9f60a081232f7475161b8d8c98826' 
  AND token = 'HZfm+njEWbIY/ay9CZwAx2DvBbU/4rmvftbsWhxhMI0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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