SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '339a50e12e98c44015231c70e37147c015def4c1986b368e58ca0ba0d42c2b64' 
  AND token = 'l+aJEx0VBYGq0w/qXbBPtmaDdPHox2Xqogl8f6fmdPU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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