SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d1caf58f98729eeab2923c26a1c97db285e50cef1fd9f7a9b7cdbc73053799e' 
  AND token = '7Omhhp3NeXNN6572EXiygwKVlMni415/zfVEBUeWnTg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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