SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1adee01cefa73cb02559a76ef6dcc06dea35c23ccfad65167f4066ae3d3bc712' 
  AND token = 'mBgafnjClnqZLAlygtpwebgOD2+B/Vps0kUUYWExpxo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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