SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aac0fb9773d24329ed8d5cd96fec1caf573eb67ca67da41e3ebf1a33ab8f0f96' 
  AND token = '5xdKENmbIchuDJHtmyiK67J54keuouqYSVm320RpeiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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