SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd62fee0e3cb19d3c4a0eacfcc9586214b0a37b810bf01c1fd38724ce42c40397' 
  AND token = '9sNw/MjxWEY5pKv3FFX0lJCs0KHTvmGWZVgvKng5Hw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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