SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '463cfcaba75f61baf6f765e53a08f4d530a76855349be97de41c0dd5e95adc76' 
  AND token = 'lD5pl/8Zrl8UHLawPlA7StpPed9AO1/usyVNw8m5lzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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