SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'fc2292c42a845e6458369befe583e9f2e9b26ae8280c37e85678814ec9f8bff1' 
  AND token = 'paIpM5tV8kxpa2+EdpEX7IPi4zRUtP68p0ByXmv+OD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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