SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d716087ff2ab051f1530e7999682a1ae63f9449aa6a823455c2acd67295d88c' 
  AND token = '2E5hVZUeppvJbnrwzCZqJGJ1JPnwVGpazcOlYiHbC+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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