SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4d6f9d93898e8fe33f2484e46f2c815a35d66d9535f69403ff39ace1c4fa810' 
  AND token = 'DuPhV+hftKK577yRwHsaWgJOukbwxo+McCs5BNbXDe4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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