SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62cdfd0e87f3fee71e434884a3ac0fc5cb983a6da8a206b9b7c6d3f3f50a4b82' 
  AND token = '+mqHSifYvWp8rMyLItgoMorJ9ytWtIbdFnOUMgw5xOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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