SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b55a4c1dfc89f79d5fd3d8e8f69bc7299cc7566829e089b22142775a7b7de072' 
  AND token = 'm32gKHG6RoUB9iTzRgu2rWK7hQnoq5dxTybPRmBNnAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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