SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '081844ba049d4bbd966907034e2e9aa638306a3eaffb49d01758f45ec170deb5' 
  AND token = 'G2nSHnSDJ+Y0vRVdYemFfQ+Y1pbZPNc9S/HBiKYjmFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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