SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97d955bf70921776266f143e35574e719ee2c784cae7293c25d50ac57847dcc0' 
  AND token = 'l1AL6kKQ0WcHXSES6Y76n+EXb4iZPMrihDxUUlZaw64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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