SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d2aef49dff6460bd09e7cfa9231f3f44aa05b3569e06f933a824fc7c4c1a04c' 
  AND token = 'cXB8FlRjJMA7AV/5CtsUw2HgClYIxwKT+nuOJ2eEtq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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