SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '944e4a43534775ead73d7befbdb7f77c804b9896a5561162ecc526c1b852adc8' 
  AND token = 'nVvqqYv4XLAZh6VKOsBmrYM625wACXQ7WjbGV5hALEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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