SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9914a776b2d6080e6f7f7b07c1e1f3a0e4b7e794f9e4c17193ffe6f256ffba97' 
  AND token = 'nZgC+MjIJoUWRaZ/eK5hUh4qupUpQt2WalilFSAsGBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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