SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '772e775f7f4a2adf4b2bc25d2e2bf37857933d8ce90ddeb497a6200e176f66b3' 
  AND token = '0jQ4JeZIcPnmZsEmUXAVjhfMj5WWASO8yrNHoecq3Go=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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