SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f0a6c4cd2bb0dc21df606ac6badeb40d1a72688605ab6f24ca70c9c723bb7f1' 
  AND token = 'V+azkldK3UhvtoXlffwBfXTFmObtSw3gRnlM+9i5yNs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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