SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b7d13ed97973cde5a205e26df1284b1890b368367a38c7411e1afc009bb5f800' 
  AND token = 'pj9b9B/zGM+NZTxHwUIdq966VI/4DxjKL3hS0l5178U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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