SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '13c62b38398034483386dd526c429bb9213fd50f1c69731f8b07f3ad1de56b21' 
  AND token = '620FiH6O8KKDGT+ynHaDdAGJdE7WPfZZEkJComCQfgw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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