SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48f3542775321983da415a50439abb404bd5b92f6d031feebbbc4885cbfb233e' 
  AND token = 'koKTJ8J2ljUxpGbKB+htLOZ9wGI3yXsAKTwQXCSKATI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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