SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bcf9701094662952538ae035a92c9ec32dd6e7cbdc48a2e207dc1368bf463bb9' 
  AND token = 'vZwOU16gJbWPPDtTnzbex3sjmJVeuRxL2WTeNnRFS4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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