SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23a19e074be64b43b677ebb025b01b3ced44e1cb464deffe5a3ac5894af5a6e0' 
  AND token = 'hW0bZnjq+Q18N3IIa5NzKqjH1ZiA/D3KnbFNOsLum/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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