SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6104a862be7f9bd45400f1a62e6b5b4c9d3f3295760548d9fd3bd4394d36f268' 
  AND token = 'FgoCGROuKxPWghrzxBq8drR/Z2ecAbGOOShH/bVvvnU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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