SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61494e3f4126ea2ae0c93ceb75798df2d2d1702735f52755c2304466a45cbcd6' 
  AND token = 'vIkryVYrKSWZ+bqIKwgm1zm02TZPhsipJxAxc1kC6dE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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