SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f52be2454d588f31e6a02e3a3a941fa9029ecdb7510c8b5f00d1469c377ee06' 
  AND token = 'pEFAytNfm/VzgTkwWGnWW7va4H3TYZsa+yDjPV8xfVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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