SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29645134e76c834d57b464830595327cb6db9a9098f56642588d23cd13f1001d' 
  AND token = 'MhSOjhvOYO6k4fVnNZe+7eR+ntk/J9JJajMn/qSsJ6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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