SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cb714c6b7f5171d3ec65ce07078b074be4394b17d10a86f08094c2128a02c4a' 
  AND token = 'ZfAmDIBO4mc5CR5tWT/t+yD+ktqqQNH7jggaiheubCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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