SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8ce0a348b842698fd17618b0e4e220db07d927f8f320b0b00a57097f0b04ee4' 
  AND token = 'ROKl8YzAPdlj8EFuCfsCQWDZpJARBUOZxwtSJWQu1H8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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