SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28b9ce2573a605c47c651783aa681d94b8bfc742f05dfd0acfe831c22832f782' 
  AND token = 'bHM5kpwKujxBKVpCTtTd74usQVSXE6VjnAFe8//Ty2A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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