SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'baabbfa461991fcadd114ea4746b03641de1283bd05ce9c14103d9beef6a6dbd' 
  AND token = 'N6Ez8jf8dK7sDS+RY5wMKAKe4lEikZDJY1tKIcdvqTo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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