SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fd59de3aa87097b09c005678acca19c477ce40c7d884a913e23a4c8c36b3dd67' 
  AND token = 'susASK3YXTtdKSP3QDNzRYBc8XogZb+41d3tQ0gR7a0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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