SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1326df0f143903e2fe2e0791d5cb5bb0a9335303c9987eec31e2f6545e411607' 
  AND token = 'WqGXtreQUqSsT9OfXZIOik5BtSSDnMqpMZYC+hqklZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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