SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'aef46eb755fabd15048667d816d2f8121352a9d1bdbeb3d12346cc3a42675a9f' 
  AND token = 'G68VujizFIHfcQv536rPPBRrKmdnuYgq/+1mpI42mQ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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