SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb2a85cef0dda2ca3bceb4a64891ff29c888521fd0c3db0d34031bff4f36c14e' 
  AND token = 'fwpQRawgEKiurDHr7FEEhPa7MjFNL6d6rof8k7Nuwjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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