SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f151648f2a15308d5c818e6fb883a42fefc34ae624f24b222899bec1b79ce6e' 
  AND token = '8GqKjZ9w9MF6r0WBQKhUvfizDYdnAAReFPyjDetmVg0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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