SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '44e7545aaf9ebd258a9642bf949f774a8b10171560bf369fd827c7ef71fde2c2' 
  AND token = 'pOhOmnwps6PZoRuins+2qx5l+XiqgvYq5TyaCkiRbDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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