SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '435f35e2df547db06f51b36514f5b811e9ebb1ccba29472599fe84fd8cfa898c' 
  AND token = 'udFFaiyr+JcWCCl99n6PVyYk+ivz62ACpEdcrViOTsU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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