SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8abe7581164613da87794fe0b6713f943df86fe3c8e9deb73ddf1d1ee44f66db' 
  AND token = '4cYmdfM32gwyepJ2lVJFpj6YywaosbWZCgT+xU6Lsd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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