SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05b1014208b3779944af4882bb1d47b95540819be6f60cb302eac28ee2a10cee' 
  AND token = 'UVzP2pymtysSzmHqiaVmsSXj6PM81T8lNtooQJE/Lvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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