SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08e052d1951b2a7c187dcb5b38dd76820e7977b50644957bfdb4a3a6c444c926' 
  AND token = 'LwuCqhGOyJ/6xJY88Bjsao3tlmfYxc2d6Sh+UA4vI/A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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