SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf405317be1439c88136464c6e4298c7266608426608069832066f4114b60730' 
  AND token = 'aV8WmUT9XfFuV45QGRqQinND/u8zUwN9nPCCOoIFWbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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