SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43abaf91008340b13f58c6ae1be7616be58e76a478e3f13472947380b62f1869' 
  AND token = 'qMIh37Fgdpx4HJmDJVM3UABoLHqTYXiRoTZQKNknUqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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