SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c08c091aa8868b3b1f2fd26a9dfda02bccc6f1e419ad8d9a695025d097e48a5c' 
  AND token = 'gKasbyjZun7UmdXekVNfbMrV3m8OT9Y860wjzw+dGak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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