SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b15f46dac2d9d222469d5e36a8a916c5fa4c5bdfbaf2990630a3ab57c5d5f20' 
  AND token = '/EkchK8D05NKL1Mzy3qyXOgB6/TstKCk+cTIAikCMp8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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