SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abc1ac71ac95fbcf7bba7d4da6b50bd54532f244b0a8804a907a24225c2dd668' 
  AND token = 'rVRgauVJJGt7wDRhAVia69NG9SNdWEXrHQcX/xB2GWU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}