SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86ba2bb070c37a29798aa15bf9026492da8572376313e194a23d3bde8cd25387' 
  AND token = 'Nr3ndI9bMuU3SBdABcJdjUFGY5lTuaZ6bqEBB4o7ypo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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