SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b4b2bef7ffd72b57a202d73695caa9bcba1c523c39c3bd146a7e645eecf5be6' 
  AND token = 'adMoLKUrkguaJ8yIEDDHRPnmdR5JBjLf7KX6Ez8XBds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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