SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd3db87285c0e16c90fb83531944560fd34432e75fd1817e733348431dbf4c29' 
  AND token = 'HkFTgzJaB7N9OLYdHEGOEsH5t7ElGMyHOcy4I6Rjwl4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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