SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bd76f198821fee36b67215a7aa9ea6f9c9c165f0afdb16208297b270ca0af49' 
  AND token = 'Qo2F2dEXIfV4KcUpDrmRGCMxxPXgzeVXGjSjgZnso2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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