SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6a84b21d2af7fb9c918ba991d880bbd5df87d69edbcdcb6cc395f7725b78d015' 
  AND token = 'vf4fEDo5WGCrFFqpXo6b0LSnQEzBKw7kzlnGvYh5BvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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