SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b6a469cf3f967ed676f10483707797b84838def9345815b6ec7c43643777a16' 
  AND token = 'TtOFQjpVGY6fKJ27zO6EUQJCdHxXJBa0WnU7lIdMiqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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