SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e850cbdfd3bb9c92ed447afa2acb2ee527870e27235c8c4093db92f4e5d711a6' 
  AND token = 'm8gu8hEa8EzqZ/QQ4lGaFznGB7UwLiKflwrnmDgh07E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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