SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35d4c46fc90006cd35e00c7bb9f4585a1d006105825edcf910bb45fa65b62f20' 
  AND token = 'TQlwz5BmFfHDWVxFbMamPM4nJwP5tMl7Nur2p51YhWA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

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