SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85b260f4ec2727ab3bcba3f21a50c53d3d58bce2896c5fe91f92c564f1fb7422' 
  AND token = 'yLLsH1YB5N2YMKU8BzsCzuBS60nRUkElhphu6PJEHrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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