SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d6802214ffd3cce1b4893cac314012acb080468ecab5bd0004fa71fdeb846d3' 
  AND token = '1qfs9EOCY2E8Cjy9MOIsyoZIpJsdJmBeTYy7Gsf66ic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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