SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af25fc5c1bb1ae89aa70b710e5971a995dde624dcd8b55e1befe1d387698fc27' 
  AND token = 'hINht2vROpnY0zGBL0qcViuIyHQzo2dUrJsCgAIP6zk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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