SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff3d60084efbd9062de8edcf1c16f1380fb99864bfe38fc005a73469dea5541e' 
  AND token = 'AHB15Nfkt8UGL8yqNSVn2XEzfZXyrrx8QqLbundFRUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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