SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bca6298b8ac960f6965345976181e9287c27edbba14aa781a535f0ff48b598b' 
  AND token = 'jwQ8ebFj61UfFSP56wBPeGOCQowMuVRh0jgvz/JY5lM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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