SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e66d09b1391a57a8aa59c758e549edb65a4015d5829c31475f301d2ee25f7354' 
  AND token = 'ThR7FljFilN+fWtBFAI8h8TfOnaqB+DklSXLPG9qoo8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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