SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d557e9d2ee7344e2001115fb03d361399ab573049cc02205cee718c7b29980d' 
  AND token = 'RccofRHLwyYyBhfutSP9SHBqZB7GQzNPthDqptuiiPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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