SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '426967f671587777ac6fc748fbf9c52c4507d34cd07b52b88f5f6dab986307cc' 
  AND token = 'zqAtrGt9RVk20NFCZhspZb5qMe0ciJDhSVEpG1DwKi0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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