SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9b8b3a40eda76c22f3e00464f23f0606e04b1e5fab99a187dd90baa4c8a530d6' 
  AND token = 'hK4ZKTkRsVSbJ+hoIZszv51FjPjoQqLFLAe7Q3qP9k4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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