SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '91570db239eb2e2a8f1d929d2d7e3b5b62d763fd89f20974b7c98d9f5f176df0' 
  AND token = 'ZsE1iidyjU/KXoUgxq6vnPSJs1V3JhW8Q9lpWDxR5Ac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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