SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bcda2704d389d5e003eac08fc619932fb9b473be49b3c3020eda213dd66e80b2' 
  AND token = 'SgXd9coDsczCQb9+Ei31V/D0dr+dp2K33YLQxdD6U/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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