SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55a9ac42b226223d5d8f2be2253d325e19882f2d83241f9fd281fe1362cef6b4' 
  AND token = 'syxiBKWtgyJLUgjWl4Hbt5Mj95LoveB7k6joETwYs/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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