SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d24cac74d1da34a86e4b98afed60c7a54bb674df8d221eac78fa353004a912d' 
  AND token = 'Yc7eG3dkMra91hCN9dN3AmXBih9AYUheimNio/iV1hg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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