SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3e6a710916cb21282e1af36cbb14539e6684b375f958dbc152204a5bc1bee04' 
  AND token = 'Qi6VDVD1R2A9qlryDMhyjkwJhJNa4cpdmOemsasbwoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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