SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f8ac19bd14f29620c57d09289d057b15eccbd05aaa8b5c95dae60429e564ab5' 
  AND token = 'AICzn08odmatzN/o9qYhv2Qdvf/TXD0jux9woqSNdGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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