SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abb5c658c719ebaa20e3ae13f347b121a15dbcfc289b68f7ad999972892eb7ee' 
  AND token = 'XSrY+8SFYffje+ZI2ijpxsnkRq9fEhgUp2RKy04fkbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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