SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '684013e67fb2d53efef69b162fe7bf842ffd2b532c6f4380c941a3c86222cd37' 
  AND token = 'Oacs4L5kBWn0kZgZXBGzaolT322DWRYXbYDvSRorx64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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