SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '788fb2d59a3020923ea1db63fbd525a0163b65d60cc4b38660e0a61dc47ee9ea' 
  AND token = 'JiKpHstcLE4R8MzC/xSAsiFVKbwx6CQd1iQTEuRKGZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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