SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f04e412e7aa8f07a9893299030fe63aeac2eb8d622cb1a9efc653b98504f070' 
  AND token = 'kbeTdOupenPWN9Ox165TnUbSi3ZcNP0pkOGV0nSs95c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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