SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f85e0153f17e6fe4bf67489cd9ba937d88c26d149b74542483a76d57bedfc82' 
  AND token = 'cKhD3c0WkxGBYr+ye4hiFTeQ/VBM6+7doUtYJmzNluU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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