SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3294a609d4d37660e64bb10e8fb8aeb3e1433300b591b0eac4965ef229c8427e' 
  AND token = 'ALnbJVFZfVCVf5j0v1jUNNAIZWrtqMYuhzuqY2cNBYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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