SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '913e318740b219e626441fa42820a905669540e0bd2b50330e563a8ce96b485f' 
  AND token = 'bZWzLUy6GBSF/3EvKJ2o0SLC8uNna287Q/ELoepWCGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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