SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd506e74ebf3c98032dbd9e76bf08c8e42334367c7fa01a7fbbf9b916b23ea33a' 
  AND token = 'oMLyF/8Kb/AEQ5bVHtOYd/xt1mWCTjxbqlHdrl5WwGg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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