SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f86f81c295442c86918b6f9660c402ae64e6eb0d6fe26c9a0f10a91983c7b47f' 
  AND token = 'JwDKGr0dIY7hMQSeBW9vwlzCokMGDVpOxE4iA5TR/jQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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