SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '445ffa576d27b461cad13060757d1fdc97a92fa47426407ac278a0fafc284122' 
  AND token = 'Vf2J6EqbgeoZzko6s1FbGAiOgVxTkrVu/nZkGdxAZB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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