SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9768cb073d7f5f34802051f4fdd76c03f928431257a6cd9d409317110161c2b0' 
  AND token = 'AYNFbx+oWvZkkWUGtfBQLZ8/gb0qxmEOaqrYCeSWwfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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