SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7dcff1cab4ab0710e4c1da0df295482b296c0f843bf9e3305bfa05d3424eacfb' 
  AND token = 'lEUszZyl2DvlMHhtPuU43uonh9mXqjJ/ndwGEwN9Zpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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