SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4178cac9e995dc7ea0ecbdf80746a3e54ec0fbff26e5091a53ef6f547e8fab7' 
  AND token = 'dee6sniG+Joz2EKGXQd19ivvDAvDvSFdjuvQAdIn22A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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