SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62677792913bbe269e1fbeed55f903394583e4242b23d1889b2c6858b7ddd33b' 
  AND token = 'Dgrzmx8KavSZeKxrRnWTZLv7YfLvhjyMgK3RHTrt7eE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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