SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e06436795914f75265da0f0611caddbb307f13c1888738dac86d3837592e11bf' 
  AND token = 'oYvglFyAeVEGzmxmIM+fWCJP7fEsIGbgskrvWnbTOqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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