SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ff87399b8da22d2c43660e60caf10e617eadc8dc6394be45b5ea10250d54221' 
  AND token = 'OYBGO4rIrJgtT95nG43MH7/SPkOo8pdfg6gp1F4cJA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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