SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1ced1fba10ba79d8c00f2689a1745073de26454315f5cac8de2f00997331d81' 
  AND token = 'cF9IO7BU/xJW2FHvNasXYPSvbVgNzBUGveZknJ2IqzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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