SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '635bd7dea67733aab790f8c4e04acfa34f57a62e5a49c3bba14b689d9b0c0fce' 
  AND token = 'JPZeoLH6yqaBFpC2HsnFrKAEzYk2/ZV2/s+T9/Tu7qY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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