SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89b3baaddc0a8273f80a069af8b15aaa68c8cb58b218606ed1ed8197f0df61bd' 
  AND token = 'Z+M2oz2yjhcWGCVmbLrwqyCuJvgr2krZzTpz4zP73hw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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