SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '041e975281d7d11db772911229b80cb3938dbcff727c94be8fa831691349157a' 
  AND token = 'lje68OYpcdbAc9pZWlQzl0R0PbWrK96zu5bvNnrdxdI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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