SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67cb849b329deb44241cc7d8d4d90ed8f4d18068da19f0d8dedbcb35ee9d0d24' 
  AND token = 'hl36ZATo910WwTKJplJQmxmQpVPw05bQ3+p1HZJVXTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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