SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f5379a78283fa0e1af56e8296178bbe77ce7b231664826e9bcba6dfbac354b8' 
  AND token = '8NdT+6BlQZmqBRknapdhAWC1gT8HHYxlfNAtq+/7uko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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