SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0405ab1c6f53b8d4966ca84f3d70799365be046e47487a45e28650a97048baa9' 
  AND token = 'rZctceeb7YMVOlI05vAiAXjJFPsBr/xOzecs1l0RUQ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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