SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4283c8c59f79d1ac88a6e586c724fb0f5987bd470ea7035a0fd7ed39c23f49f' 
  AND token = 'OmYn/XnqR+gqboSZN912nupwaXQaT1SasXJ+sOHUlBg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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