SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3b9a43bb5776e48c482d6c6d7c99d754606cbef14fe3669769ee94d54ae04680' 
  AND token = 'OrI8zG/DPhtHzwTo9et9fSuyqjH+uVX12n9W58As+90=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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