SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5656067752e150e76b703b85abbc4f1b8596eaf282f7c9e613002ff95300efa7' 
  AND token = 'JDFxBCgVv5p70p82aICZgR6nLjXQssDs1x0JlY1vQNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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