SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '956b45caa8a9b3e6e73227e33939f9497d9e6ff2dc4ae13c740f8679603565e8' 
  AND token = 'UT97xr8uKV3hNC7pyaoBj2fgB6HKJq/pVy0h+lDX4vg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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