SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ebdff56773b5aee4b404612f1d6e98e99ad0595feaf66afaee77195285b62f1' 
  AND token = 'SPoBpK/J/TMtZ/lABoXJcbcHTQEH5fqeQV1bWMyX7Jk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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