SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad7e883449eeccdc65ae32299f6c25643f00f0e641b687bc4f6af90dd41ae858' 
  AND token = 'IQ2pus7dtBvdfEW0ANqPqxwB6uvlYLzKr61otoOjg90=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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