SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd0d690c8cd7cb44bc3f59cbeb0274826d3bcbde7a481c3bcaf9c832643f12a51' 
  AND token = 'Kk3qiwEk8yTlDK7ikx6xJNhWnCGpxZVhaR5Yg6nJfNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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