SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64adb2fc83bed652c221b76b111fab527749449cf5a2226ab370dd5e2964446c' 
  AND token = 'K/Rq4Yjhw03sjGVvPMSrjFR1eAqXC7MjYrL4rQ2+G8k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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