SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '522c1d19db7e0fc2585b61341305a77bf344c86faac17f9bfea593c998dce4a7' 
  AND token = 'dNIqM5sx1W5fS4ZiVZG6zQhhIoElo4xvO4wQHOVjmXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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