SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3610a5dec60ec2bf5c40e7298de1e417d518f7cd32623a835c7802b74d433a96' 
  AND token = 'YvH9emtG265wU86epvIRQ4KPEYkXGnl/OGIn42zV9XI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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