SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '532f6c8f8369c3155913c821ec20d50a9ddb47e0090792f8f22d8e58e340a30c' 
  AND token = '2UpHXDAGRkGr70hcQcyMsEe1s+oRFSqgjDlSaoPH45E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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