SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4488c4358894b9b20c51095ae6661286540601d6c603fc90cfc82d98ba531ee7' 
  AND token = '5cEGg35KHFjBR0wUY67+XfjzX3PvFqsU+qbHsC8uZ/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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