SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '253b5969f1fbb05c238a9bc5870a52c80052aabe8c738b061bfed2ed72cd19a0' 
  AND token = 'Zjv67RtF1VHFm66cAgyJX+W4BGe213mX6zwMNBkfK6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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