SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c9a0bc041c551816606fbc57065add3deb8a055c227595e46e64a20e885d9a9' 
  AND token = '7PskTfoV6F/Ewh5Fiw4c7gsNvU6fRbszYq79PuXP8C8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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