SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69bf7ab8a681c2ea14cf84331919bac4c92576175ebf9e15de4d12f1cf265093' 
  AND token = '1qUJj1ZGciS5pso65PibS0GPMy2cOcI3XcY2rVZNxpo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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