SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ac36bef8c424824c11c2cfbfb37648857770e41d182ca1b1687f55c76e0cc89' 
  AND token = 'JTjLfwcy9bUj0C5gVr9C9bYKbogbURRsn6UvRxvG87A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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