SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46cb06785600b2eae05a814062899acf9ea3812a83f361cc604b5f549d8f8ad1' 
  AND token = '8NKsC7uWxQ9F/yxt2+u+fd8RseAKNpPIsuMGm2V4Su8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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