SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b092d313ca07096373c2c363ac18b7fe36dc9c715ee5d9e85fa5f52b4cbd8eea' 
  AND token = 'Zv/2KplS82PxpvEW2KfQEwqwzvsYq0+h6mVydAsl+IY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}