SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '84436da5c82f9559875ff2497986168cd4f5cfc346f2cd53d371d4301e665814' 
  AND token = 'uVYbFPY1BSuWrai8HCmd9ihayWlzf1kAimc7Fd3kINk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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