SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '658c5fade65088edf763587e82c7816a6842f099b55e3495e91ab309bdfe5d38' 
  AND token = 'IKCu/miifS8IPXkdHqn85lQNM/9doEv02CQJk8Db2Hs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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