SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1a60a6d2e1c1d91821f6066d205484f991cb4a08ec34af7fa8867eac60b89431' 
  AND token = 'S8sNAxe4WfxizBfbpAPkuywvb0LoUw6rMjZzIh1GYls=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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