SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99819f0ba2f65d9092e8281d773ef1c26690c5fb8dae067fabf38668f163e441' 
  AND token = 'ko3RzWK/ASh9woBeR867i6v1xSzkwp92Vn6JtzCWqDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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