SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b82bfacdd543d54ec501e801bd24fc4f209e5f99dec31ed3c090284f0525330' 
  AND token = 'GQYlvjsA6ymW8/gRYoCcXBpUZxOHr5nxcdll2ixeG1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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