SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'b297ee8a927c70a177afbf37eff3db108d425e380318da9d0b7f4f0245f42428' 
  AND token = 'jlzyW3IJ0fkTjgLjiLLdrAjWKzq1sX+CH/t6hpU0bfA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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