SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad0ee5fd1151a1dafb165cc71dac113e23b6287d7bb34271610e28ea3479f6bf' 
  AND token = 'i/MdWJJv7PlGkjKgGubtraz7bIwZD2ZClxABNPbfSto=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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