SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f346751ce5072c5fba7dca3bea3b20e3cafca0d5a26cc217224957b124580012' 
  AND token = 'cB8OUyR14orbmJB/4a1G90pYb2z8wLtgItz8aIf0PGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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