SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'c195f043140b8567fa4289d4b1cad28b3d2c518d8698e4391baeb8d1e0c0f7d6' 
  AND token = 'FbK09FHNxg+nS5mrBVeXwYxv/POk7UJRYqeNfMClZd8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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