SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4164ffc6a8688a3afa4fd3e0102e007650b7ce7709738e9f69169f1b020233e0' 
  AND token = '9w8N3oNqc4igzp3WmLWfn6qRI7SQAizlNsFZO20Oaik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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