SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1d08d453a437887bfc12e037313a43a3c42481c8df6c0e96d31e7a589e1c3408' 
  AND token = 'wzh/PUHEVWvh2L7T5xjZM9vazf0DRdYgWMgZBsK/Evo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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